feat: TUI Phase 1 common widgets + scoring/path beads

bd-26f2: Common widgets (render_breadcrumb, render_status_bar,
render_loading, render_error_toast, render_help_overlay) + render_screen
top-level dispatch wired to LoreApp::view(). 27 widget tests.

bd-2w1p: Add half-life fields to ScoringConfig with validation.
bd-1soz: Add half_life_decay() pure function.
bd-18dn: Add normalize_query_path() for path canonicalization.

Phase 1 modules: CommandRegistry, NavigationStack, CrashContext,
TaskSupervisor, AppState with per-screen states.

172 lore-tui tests passing, clippy clean, fmt clean.

.beads/last-touched

@@ -1 +1 @@
-bd-20p9
+bd-26f2

crates/lore-tui/Cargo.lock

@@ -1335,6 +1335,9 @@ dependencies = [
  "lore",
  "regex",
  "rusqlite",
+ "serde",
+ "serde_json",
+ "tempfile",
 ]
 
 [[package]]

crates/lore-tui/Cargo.toml

@@ -35,5 +35,12 @@ rusqlite = { version = "0.38", features = ["bundled"] }
 # Terminal (crossterm for raw mode + event reading, used by ftui runtime)
 crossterm = "0.28"
 
+# Serialization (crash context NDJSON dumps)
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+
 # Regex (used by safety module for PII/secret redaction)
 regex = "1"
+
+[dev-dependencies]
+tempfile = "3"

crates/lore-tui/src/app.rs

@@ -1,14 +1,26 @@
-#![allow(dead_code)] // Phase 0: minimal scaffold, fleshed out in bd-6pmy
+#![allow(dead_code)] // Phase 1: methods consumed as screens are implemented
 
-//! Minimal FrankenTUI Model implementation for the lore TUI.
+//! Full FrankenTUI Model implementation for the lore TUI.
 //!
-//! This is the Phase 0 integration proof — validates that the ftui Model trait
-//! compiles with our Msg type and produces basic output. The full LoreApp with
-//! screen routing, navigation stack, and action dispatch comes in bd-6pmy.
+//! LoreApp is the central coordinator: it owns all state, dispatches
+//! messages through a 5-stage key pipeline, records crash context
+//! breadcrumbs, manages async tasks via the supervisor, and routes
+//! view() to per-screen render functions.
 
-use ftui::{Cmd, Frame, Model};
+use chrono::TimeDelta;
+use ftui::{Cmd, Event, Frame, KeyCode, KeyEvent, Model, Modifiers};
 
-use crate::message::Msg;
+use crate::clock::{Clock, SystemClock};
+use crate::commands::{CommandRegistry, build_registry};
+use crate::crash_context::{CrashContext, CrashEvent};
+use crate::db::DbManager;
+use crate::message::{InputMode, Msg, Screen};
+use crate::navigation::NavigationStack;
+use crate::state::{AppState, LoadState};
+use crate::task_supervisor::{TaskKey, TaskSupervisor};
+
+/// Timeout for the g-prefix key sequence.
+const GO_PREFIX_TIMEOUT: TimeDelta = TimeDelta::milliseconds(500);
 
 // ---------------------------------------------------------------------------
 // LoreApp
@@ -16,49 +28,414 @@ use crate::message::Msg;
 
 /// Root model for the lore TUI.
 ///
-/// Phase 0: minimal scaffold that renders a placeholder and handles Quit.
-/// Phase 1 (bd-6pmy) will add screen routing, DbManager, theme, and subscriptions.
-pub struct LoreApp;
+/// Owns all state and implements the FrankenTUI Model trait. The
+/// update() method is the single entry point for all state transitions.
+pub struct LoreApp {
+    pub state: AppState,
+    pub navigation: NavigationStack,
+    pub supervisor: TaskSupervisor,
+    pub crash_context: CrashContext,
+    pub command_registry: CommandRegistry,
+    pub input_mode: InputMode,
+    pub clock: Box<dyn Clock>,
+    pub db: Option<DbManager>,
+}
+
+impl LoreApp {
+    /// Create a new LoreApp with default state.
+    ///
+    /// Uses a real system clock and no DB connection (set separately).
+    #[must_use]
+    pub fn new() -> Self {
+        Self {
+            state: AppState::default(),
+            navigation: NavigationStack::new(),
+            supervisor: TaskSupervisor::new(),
+            crash_context: CrashContext::new(),
+            command_registry: build_registry(),
+            input_mode: InputMode::Normal,
+            clock: Box::new(SystemClock),
+            db: None,
+        }
+    }
+
+    /// Create a LoreApp for testing with a custom clock.
+    #[cfg(test)]
+    fn with_clock(clock: Box<dyn Clock>) -> Self {
+        Self {
+            clock,
+            ..Self::new()
+        }
+    }
+
+    // -----------------------------------------------------------------------
+    // Key dispatch
+    // -----------------------------------------------------------------------
+
+    /// Normalize terminal key variants for cross-terminal consistency.
+    fn normalize_key(key: &mut KeyEvent) {
+        // BackTab -> Shift+Tab canonical form.
+        if key.code == KeyCode::BackTab {
+            key.code = KeyCode::Tab;
+            key.modifiers |= Modifiers::SHIFT;
+        }
+    }
+
+    /// 5-stage key dispatch pipeline.
+    ///
+    /// Returns the Cmd to execute (Quit, None, or a task command).
+    fn interpret_key(&mut self, mut key: KeyEvent) -> Cmd<Msg> {
+        Self::normalize_key(&mut key);
+
+        let screen = self.navigation.current().clone();
+
+        // Record key press in crash context.
+        self.crash_context.push(CrashEvent::KeyPress {
+            key: format!("{:?}", key.code),
+            mode: format!("{:?}", self.input_mode),
+            screen: screen.label().to_string(),
+        });
+
+        // --- Stage 1: Quit check ---
+        // Ctrl+C always quits regardless of mode.
+        if key.code == KeyCode::Char('c') && key.modifiers.contains(Modifiers::CTRL) {
+            return Cmd::quit();
+        }
+
+        // --- Stage 2: InputMode routing ---
+        match &self.input_mode {
+            InputMode::Text => {
+                return self.handle_text_mode_key(&key, &screen);
+            }
+            InputMode::Palette => {
+                return self.handle_palette_mode_key(&key, &screen);
+            }
+            InputMode::GoPrefix { started_at } => {
+                let elapsed = self.clock.now().signed_duration_since(*started_at);
+                if elapsed > GO_PREFIX_TIMEOUT {
+                    // Timeout expired — cancel prefix and re-process as normal.
+                    self.input_mode = InputMode::Normal;
+                } else {
+                    return self.handle_go_prefix_key(&key, &screen);
+                }
+            }
+            InputMode::Normal => {}
+        }
+
+        // --- Stage 3: Global shortcuts (Normal mode) ---
+        // 'q' quits.
+        if key.code == KeyCode::Char('q') && key.modifiers == Modifiers::NONE {
+            return Cmd::quit();
+        }
+
+        // 'g' starts prefix sequence.
+        if self
+            .command_registry
+            .is_sequence_starter(&key.code, &key.modifiers)
+        {
+            self.input_mode = InputMode::GoPrefix {
+                started_at: self.clock.now(),
+            };
+            return Cmd::none();
+        }
+
+        // Registry-based single-key lookup.
+        if let Some(cmd_def) =
+            self.command_registry
+                .lookup_key(&key.code, &key.modifiers, &screen, &self.input_mode)
+        {
+            return self.execute_command(cmd_def.id, &screen);
+        }
+
+        // --- Stage 4: Screen-local keys ---
+        // Delegated to AppState::interpret_screen_key in future phases.
+
+        // --- Stage 5: Fallback (unhandled) ---
+        Cmd::none()
+    }
+
+    /// Handle keys in Text input mode.
+    ///
+    /// Only Esc and Ctrl+P pass through; everything else is consumed by
+    /// the focused text widget (handled in future phases).
+    fn handle_text_mode_key(&mut self, key: &KeyEvent, screen: &Screen) -> Cmd<Msg> {
+        // Esc blurs the text input.
+        if key.code == KeyCode::Escape {
+            self.state.blur_text_focus();
+            self.input_mode = InputMode::Normal;
+            return Cmd::none();
+        }
+
+        // Ctrl+P opens palette even in text mode.
+        if let Some(cmd_def) =
+            self.command_registry
+                .lookup_key(&key.code, &key.modifiers, screen, &InputMode::Text)
+        {
+            return self.execute_command(cmd_def.id, screen);
+        }
+
+        // All other keys consumed by text widget (future).
+        Cmd::none()
+    }
+
+    /// Handle keys in Palette mode.
+    fn handle_palette_mode_key(&mut self, key: &KeyEvent, _screen: &Screen) -> Cmd<Msg> {
+        if key.code == KeyCode::Escape {
+            self.input_mode = InputMode::Normal;
+            return Cmd::none();
+        }
+        // Palette key dispatch will be expanded in the palette widget phase.
+        Cmd::none()
+    }
+
+    /// Handle the second key of a g-prefix sequence.
+    fn handle_go_prefix_key(&mut self, key: &KeyEvent, screen: &Screen) -> Cmd<Msg> {
+        self.input_mode = InputMode::Normal;
+
+        if let Some(cmd_def) = self.command_registry.complete_sequence(
+            &KeyCode::Char('g'),
+            &Modifiers::NONE,
+            &key.code,
+            &key.modifiers,
+            screen,
+        ) {
+            return self.execute_command(cmd_def.id, screen);
+        }
+
+        // Invalid second key — cancel prefix silently.
+        Cmd::none()
+    }
+
+    /// Execute a command by ID.
+    fn execute_command(&mut self, id: &str, _screen: &Screen) -> Cmd<Msg> {
+        match id {
+            "quit" => Cmd::quit(),
+            "go_back" => {
+                self.navigation.pop();
+                Cmd::none()
+            }
+            "show_help" => {
+                self.state.show_help = !self.state.show_help;
+                Cmd::none()
+            }
+            "command_palette" => {
+                self.input_mode = InputMode::Palette;
+                self.state.command_palette.query_focused = true;
+                Cmd::none()
+            }
+            "open_in_browser" => {
+                // Will dispatch OpenInBrowser msg in future phase.
+                Cmd::none()
+            }
+            "show_cli" => {
+                // Will show CLI equivalent in future phase.
+                Cmd::none()
+            }
+            "go_home" => self.navigate_to(Screen::Dashboard),
+            "go_issues" => self.navigate_to(Screen::IssueList),
+            "go_mrs" => self.navigate_to(Screen::MrList),
+            "go_search" => self.navigate_to(Screen::Search),
+            "go_timeline" => self.navigate_to(Screen::Timeline),
+            "go_who" => self.navigate_to(Screen::Who),
+            "go_sync" => self.navigate_to(Screen::Sync),
+            "jump_back" => {
+                self.navigation.jump_back();
+                Cmd::none()
+            }
+            "jump_forward" => {
+                self.navigation.jump_forward();
+                Cmd::none()
+            }
+            "move_down" | "move_up" | "select_item" | "focus_filter" | "scroll_to_top" => {
+                // Screen-specific actions — delegated in future phases.
+                Cmd::none()
+            }
+            _ => Cmd::none(),
+        }
+    }
+
+    // -----------------------------------------------------------------------
+    // Navigation helpers
+    // -----------------------------------------------------------------------
+
+    /// Navigate to a screen, pushing the nav stack and starting a data load.
+    fn navigate_to(&mut self, screen: Screen) -> Cmd<Msg> {
+        let screen_label = screen.label().to_string();
+        let current_label = self.navigation.current().label().to_string();
+
+        self.crash_context.push(CrashEvent::StateTransition {
+            from: current_label,
+            to: screen_label,
+        });
+
+        self.navigation.push(screen.clone());
+        self.state
+            .set_loading(screen.clone(), LoadState::Refreshing);
+
+        // Spawn supervised task for data loading (placeholder — actual DB
+        // query dispatch comes in Phase 2 screen implementations).
+        let _handle = self.supervisor.submit(TaskKey::LoadScreen(screen));
+
+        Cmd::none()
+    }
+
+    // -----------------------------------------------------------------------
+    // Message dispatch (non-key)
+    // -----------------------------------------------------------------------
+
+    /// Handle non-key messages.
+    fn handle_msg(&mut self, msg: Msg) -> Cmd<Msg> {
+        // Record in crash context.
+        self.crash_context.push(CrashEvent::MsgDispatched {
+            msg_name: format!("{msg:?}")
+                .split('(')
+                .next()
+                .unwrap_or("?")
+                .to_string(),
+            screen: self.navigation.current().label().to_string(),
+        });
+
+        match msg {
+            Msg::Quit => Cmd::quit(),
+
+            // --- Navigation ---
+            Msg::NavigateTo(screen) => self.navigate_to(screen),
+            Msg::GoBack => {
+                self.navigation.pop();
+                Cmd::none()
+            }
+            Msg::GoForward => {
+                self.navigation.go_forward();
+                Cmd::none()
+            }
+            Msg::GoHome => self.navigate_to(Screen::Dashboard),
+            Msg::JumpBack(_) => {
+                self.navigation.jump_back();
+                Cmd::none()
+            }
+            Msg::JumpForward(_) => {
+                self.navigation.jump_forward();
+                Cmd::none()
+            }
+
+            // --- Error ---
+            Msg::Error(err) => {
+                self.state.set_error(err.to_string());
+                Cmd::none()
+            }
+
+            // --- Help / UI ---
+            Msg::ShowHelp => {
+                self.state.show_help = !self.state.show_help;
+                Cmd::none()
+            }
+            Msg::BlurTextInput => {
+                self.state.blur_text_focus();
+                self.input_mode = InputMode::Normal;
+                Cmd::none()
+            }
+
+            // --- Terminal ---
+            Msg::Resize { width, height } => {
+                self.state.terminal_size = (width, height);
+                Cmd::none()
+            }
+            Msg::Tick => Cmd::none(),
+
+            // --- Loaded results (stale guard) ---
+            Msg::IssueListLoaded { generation, rows } => {
+                if self
+                    .supervisor
+                    .is_current(&TaskKey::LoadScreen(Screen::IssueList), generation)
+                {
+                    self.state.issue_list.rows = rows;
+                    self.state.set_loading(Screen::IssueList, LoadState::Idle);
+                    self.supervisor
+                        .complete(&TaskKey::LoadScreen(Screen::IssueList), generation);
+                }
+                Cmd::none()
+            }
+            Msg::MrListLoaded { generation, rows } => {
+                if self
+                    .supervisor
+                    .is_current(&TaskKey::LoadScreen(Screen::MrList), generation)
+                {
+                    self.state.mr_list.rows = rows;
+                    self.state.set_loading(Screen::MrList, LoadState::Idle);
+                    self.supervisor
+                        .complete(&TaskKey::LoadScreen(Screen::MrList), generation);
+                }
+                Cmd::none()
+            }
+            Msg::DashboardLoaded { generation, data } => {
+                if self
+                    .supervisor
+                    .is_current(&TaskKey::LoadScreen(Screen::Dashboard), generation)
+                {
+                    self.state.dashboard.issue_count = data.issue_count;
+                    self.state.dashboard.mr_count = data.mr_count;
+                    self.state.set_loading(Screen::Dashboard, LoadState::Idle);
+                    self.supervisor
+                        .complete(&TaskKey::LoadScreen(Screen::Dashboard), generation);
+                }
+                Cmd::none()
+            }
+
+            // All other message variants: no-op for now.
+            // Future phases will fill these in as screens are implemented.
+            _ => Cmd::none(),
+        }
+    }
+}
+
+impl Default for LoreApp {
+    fn default() -> Self {
+        Self::new()
+    }
+}
 
 impl Model for LoreApp {
     type Message = Msg;
 
     fn init(&mut self) -> Cmd<Self::Message> {
+        // Install crash context panic hook.
+        CrashContext::install_panic_hook(&self.crash_context);
+        CrashContext::prune_crash_files();
+
+        // Navigate to dashboard (will trigger data load in future phase).
         Cmd::none()
     }
 
     fn update(&mut self, msg: Self::Message) -> Cmd<Self::Message> {
-        match msg {
-            Msg::Quit => Cmd::quit(),
-            _ => Cmd::none(),
-        }
+        // Route raw key events through the 5-stage pipeline.
+        if let Msg::RawEvent(Event::Key(key)) = msg {
+            return self.interpret_key(key);
         }
 
-    fn view(&self, _frame: &mut Frame) {
-        // Phase 0: no-op view. Phase 1 will render screens via the frame.
+        // Everything else goes through message dispatch.
+        self.handle_msg(msg)
+    }
+
+    fn view(&self, frame: &mut Frame) {
+        crate::view::render_screen(frame, self);
     }
 }
 
-/// Verify that `App::fullscreen(LoreApp).run()` compiles.
-///
-/// This is a compile-time check — we don't actually run it because that
-/// would require a real TTY. The function exists solely to prove the wiring.
+/// Verify that `App::fullscreen(LoreApp::new()).run()` compiles.
 #[cfg(test)]
 fn _assert_app_fullscreen_compiles() {
-    // This function is never called — it only needs to compile.
     fn _inner() {
         use ftui::App;
-        let _app_builder = App::fullscreen(LoreApp);
-        // _app_builder.run() would need a TTY, so we don't call it.
+        let _app_builder = App::fullscreen(LoreApp::new());
     }
 }
 
-/// Verify that `App::inline(LoreApp, 12).run()` compiles.
+/// Verify that `App::inline(LoreApp::new(), 12).run()` compiles.
 #[cfg(test)]
 fn _assert_app_inline_compiles() {
     fn _inner() {
         use ftui::App;
-        let _app_builder = App::inline(LoreApp, 12);
+        let _app_builder = App::inline(LoreApp::new(), 12);
     }
 }
 
@@ -69,33 +446,267 @@ fn _assert_app_inline_compiles() {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::clock::FakeClock;
+
+    fn test_app() -> LoreApp {
+        LoreApp::with_clock(Box::new(FakeClock::new(chrono::Utc::now())))
+    }
 
     #[test]
     fn test_lore_app_init_returns_none() {
-        let mut app = LoreApp;
+        let mut app = test_app();
         let cmd = app.init();
         assert!(matches!(cmd, Cmd::None));
     }
 
     #[test]
     fn test_lore_app_quit_returns_quit_cmd() {
-        let mut app = LoreApp;
+        let mut app = test_app();
         let cmd = app.update(Msg::Quit);
         assert!(matches!(cmd, Cmd::Quit));
     }
 
     #[test]
     fn test_lore_app_tick_returns_none() {
-        let mut app = LoreApp;
+        let mut app = test_app();
         let cmd = app.update(Msg::Tick);
         assert!(matches!(cmd, Cmd::None));
     }
 
     #[test]
-    fn test_lore_app_navigate_returns_none() {
-        use crate::message::Screen;
-        let mut app = LoreApp;
-        let cmd = app.update(Msg::NavigateTo(Screen::Dashboard));
+    fn test_lore_app_navigate_to_updates_nav_stack() {
+        let mut app = test_app();
+        let cmd = app.update(Msg::NavigateTo(Screen::IssueList));
+        assert!(matches!(cmd, Cmd::None));
+        assert!(app.navigation.is_at(&Screen::IssueList));
+        assert_eq!(app.navigation.depth(), 2);
+    }
+
+    #[test]
+    fn test_lore_app_go_back() {
+        let mut app = test_app();
+        app.update(Msg::NavigateTo(Screen::IssueList));
+        app.update(Msg::GoBack);
+        assert!(app.navigation.is_at(&Screen::Dashboard));
+    }
+
+    #[test]
+    fn test_lore_app_go_forward() {
+        let mut app = test_app();
+        app.update(Msg::NavigateTo(Screen::IssueList));
+        app.update(Msg::GoBack);
+        app.update(Msg::GoForward);
+        assert!(app.navigation.is_at(&Screen::IssueList));
+    }
+
+    #[test]
+    fn test_ctrl_c_always_quits() {
+        let mut app = test_app();
+        let key = KeyEvent::new(KeyCode::Char('c')).with_modifiers(Modifiers::CTRL);
+        let cmd = app.update(Msg::RawEvent(Event::Key(key)));
+        assert!(matches!(cmd, Cmd::Quit));
+    }
+
+    #[test]
+    fn test_q_key_quits_in_normal_mode() {
+        let mut app = test_app();
+        let key = KeyEvent::new(KeyCode::Char('q'));
+        let cmd = app.update(Msg::RawEvent(Event::Key(key)));
+        assert!(matches!(cmd, Cmd::Quit));
+    }
+
+    #[test]
+    fn test_q_key_blocked_in_text_mode() {
+        let mut app = test_app();
+        app.input_mode = InputMode::Text;
+        let key = KeyEvent::new(KeyCode::Char('q'));
+        let cmd = app.update(Msg::RawEvent(Event::Key(key)));
+        // q in text mode should NOT quit.
         assert!(matches!(cmd, Cmd::None));
     }
+
+    #[test]
+    fn test_esc_blurs_text_mode() {
+        let mut app = test_app();
+        app.input_mode = InputMode::Text;
+        app.state.search.query_focused = true;
+
+        let key = KeyEvent::new(KeyCode::Escape);
+        app.update(Msg::RawEvent(Event::Key(key)));
+
+        assert!(matches!(app.input_mode, InputMode::Normal));
+        assert!(!app.state.has_text_focus());
+    }
+
+    #[test]
+    fn test_g_prefix_enters_go_mode() {
+        let mut app = test_app();
+        let key = KeyEvent::new(KeyCode::Char('g'));
+        app.update(Msg::RawEvent(Event::Key(key)));
+        assert!(matches!(app.input_mode, InputMode::GoPrefix { .. }));
+    }
+
+    #[test]
+    fn test_g_then_i_navigates_to_issues() {
+        let mut app = test_app();
+
+        // First key: 'g'
+        let key_g = KeyEvent::new(KeyCode::Char('g'));
+        app.update(Msg::RawEvent(Event::Key(key_g)));
+
+        // Second key: 'i'
+        let key_i = KeyEvent::new(KeyCode::Char('i'));
+        app.update(Msg::RawEvent(Event::Key(key_i)));
+
+        assert!(app.navigation.is_at(&Screen::IssueList));
+    }
+
+    #[test]
+    fn test_go_prefix_timeout_cancels() {
+        let clock = FakeClock::new(chrono::Utc::now());
+        let mut app = LoreApp::with_clock(Box::new(clock.clone()));
+
+        // Press 'g'.
+        let key_g = KeyEvent::new(KeyCode::Char('g'));
+        app.update(Msg::RawEvent(Event::Key(key_g)));
+        assert!(matches!(app.input_mode, InputMode::GoPrefix { .. }));
+
+        // Advance clock past timeout.
+        clock.advance(TimeDelta::milliseconds(600));
+
+        // Press 'i' after timeout — should NOT navigate to issues.
+        let key_i = KeyEvent::new(KeyCode::Char('i'));
+        app.update(Msg::RawEvent(Event::Key(key_i)));
+
+        // Should still be at Dashboard (no navigation happened).
+        assert!(app.navigation.is_at(&Screen::Dashboard));
+        assert!(matches!(app.input_mode, InputMode::Normal));
+    }
+
+    #[test]
+    fn test_show_help_toggles() {
+        let mut app = test_app();
+        assert!(!app.state.show_help);
+
+        app.update(Msg::ShowHelp);
+        assert!(app.state.show_help);
+
+        app.update(Msg::ShowHelp);
+        assert!(!app.state.show_help);
+    }
+
+    #[test]
+    fn test_error_msg_sets_toast() {
+        let mut app = test_app();
+        app.update(Msg::Error(crate::message::AppError::DbBusy));
+        assert!(app.state.error_toast.is_some());
+        assert!(app.state.error_toast.as_ref().unwrap().contains("busy"));
+    }
+
+    #[test]
+    fn test_resize_updates_terminal_size() {
+        let mut app = test_app();
+        app.update(Msg::Resize {
+            width: 120,
+            height: 40,
+        });
+        assert_eq!(app.state.terminal_size, (120, 40));
+    }
+
+    #[test]
+    fn test_stale_result_dropped() {
+        let mut app = test_app();
+
+        // Submit two tasks for IssueList — second supersedes first.
+        let gen1 = app
+            .supervisor
+            .submit(TaskKey::LoadScreen(Screen::IssueList))
+            .generation;
+        let gen2 = app
+            .supervisor
+            .submit(TaskKey::LoadScreen(Screen::IssueList))
+            .generation;
+
+        // Stale result with gen1 should be ignored.
+        app.update(Msg::IssueListLoaded {
+            generation: gen1,
+            rows: vec![crate::message::IssueRow {
+                key: crate::message::EntityKey::issue(1, 1),
+                title: "stale".into(),
+                state: "opened".into(),
+            }],
+        });
+        assert!(app.state.issue_list.rows.is_empty());
+
+        // Current result with gen2 should be applied.
+        app.update(Msg::IssueListLoaded {
+            generation: gen2,
+            rows: vec![crate::message::IssueRow {
+                key: crate::message::EntityKey::issue(1, 2),
+                title: "fresh".into(),
+                state: "opened".into(),
+            }],
+        });
+        assert_eq!(app.state.issue_list.rows.len(), 1);
+        assert_eq!(app.state.issue_list.rows[0].title, "fresh");
+    }
+
+    #[test]
+    fn test_crash_context_records_events() {
+        let mut app = test_app();
+        app.update(Msg::Tick);
+        app.update(Msg::NavigateTo(Screen::IssueList));
+
+        // Should have recorded at least 2 events.
+        assert!(app.crash_context.len() >= 2);
+    }
+
+    #[test]
+    fn test_navigate_sets_loading_state() {
+        let mut app = test_app();
+        app.update(Msg::NavigateTo(Screen::IssueList));
+        assert_eq!(
+            *app.state.load_state.get(&Screen::IssueList),
+            LoadState::Refreshing
+        );
+    }
+
+    #[test]
+    fn test_command_palette_opens_from_ctrl_p() {
+        let mut app = test_app();
+        let key = KeyEvent::new(KeyCode::Char('p')).with_modifiers(Modifiers::CTRL);
+        app.update(Msg::RawEvent(Event::Key(key)));
+        assert!(matches!(app.input_mode, InputMode::Palette));
+        assert!(app.state.command_palette.query_focused);
+    }
+
+    #[test]
+    fn test_esc_closes_palette() {
+        let mut app = test_app();
+        app.input_mode = InputMode::Palette;
+
+        let key = KeyEvent::new(KeyCode::Escape);
+        app.update(Msg::RawEvent(Event::Key(key)));
+
+        assert!(matches!(app.input_mode, InputMode::Normal));
+    }
+
+    #[test]
+    fn test_blur_text_input_msg() {
+        let mut app = test_app();
+        app.input_mode = InputMode::Text;
+        app.state.search.query_focused = true;
+
+        app.update(Msg::BlurTextInput);
+
+        assert!(matches!(app.input_mode, InputMode::Normal));
+        assert!(!app.state.has_text_focus());
+    }
+
+    #[test]
+    fn test_default_is_new() {
+        let app = LoreApp::default();
+        assert!(app.navigation.is_at(&Screen::Dashboard));
+        assert!(matches!(app.input_mode, InputMode::Normal));
+    }
 }

crates/lore-tui/src/commands.rs

@@ -0,0 +1,807 @@
+#![allow(dead_code)] // Phase 1: consumed by LoreApp in bd-6pmy
+
+//! Command registry — single source of truth for all TUI actions.
+//!
+//! Every keybinding, palette entry, help text, CLI equivalent, and
+//! status hint is generated from [`CommandRegistry`]. No hardcoded
+//! duplicate maps exist in view/state modules.
+//!
+//! Supports single-key and two-key sequences (g-prefix vim bindings).
+
+use std::collections::HashMap;
+
+use ftui::{KeyCode, Modifiers};
+
+use crate::message::{InputMode, Screen};
+
+// ---------------------------------------------------------------------------
+// Key formatting
+// ---------------------------------------------------------------------------
+
+/// Format a key code + modifiers as a human-readable string.
+fn format_key(code: KeyCode, modifiers: Modifiers) -> String {
+    let mut parts = Vec::new();
+    if modifiers.contains(Modifiers::CTRL) {
+        parts.push("Ctrl");
+    }
+    if modifiers.contains(Modifiers::ALT) {
+        parts.push("Alt");
+    }
+    if modifiers.contains(Modifiers::SHIFT) {
+        parts.push("Shift");
+    }
+    let key_name = match code {
+        KeyCode::Char(c) => c.to_string(),
+        KeyCode::Enter => "Enter".to_string(),
+        KeyCode::Escape => "Esc".to_string(),
+        KeyCode::Tab => "Tab".to_string(),
+        KeyCode::Backspace => "Backspace".to_string(),
+        KeyCode::Delete => "Del".to_string(),
+        KeyCode::Up => "Up".to_string(),
+        KeyCode::Down => "Down".to_string(),
+        KeyCode::Left => "Left".to_string(),
+        KeyCode::Right => "Right".to_string(),
+        KeyCode::Home => "Home".to_string(),
+        KeyCode::End => "End".to_string(),
+        KeyCode::PageUp => "PgUp".to_string(),
+        KeyCode::PageDown => "PgDn".to_string(),
+        KeyCode::F(n) => format!("F{n}"),
+        _ => "?".to_string(),
+    };
+    parts.push(&key_name);
+    // We need to own the joined string.
+    let joined: String = parts.join("+");
+    joined
+}
+
+// ---------------------------------------------------------------------------
+// KeyCombo
+// ---------------------------------------------------------------------------
+
+/// A keybinding: either a single key or a two-key sequence.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum KeyCombo {
+    /// Single key press (e.g., `q`, `Esc`, `Ctrl+P`).
+    Single { code: KeyCode, modifiers: Modifiers },
+    /// Two-key sequence (e.g., `g` then `i` for go-to-issues).
+    Sequence {
+        first_code: KeyCode,
+        first_modifiers: Modifiers,
+        second_code: KeyCode,
+        second_modifiers: Modifiers,
+    },
+}
+
+impl KeyCombo {
+    /// Convenience: single key with no modifiers.
+    #[must_use]
+    pub const fn key(code: KeyCode) -> Self {
+        Self::Single {
+            code,
+            modifiers: Modifiers::NONE,
+        }
+    }
+
+    /// Convenience: single key with Ctrl modifier.
+    #[must_use]
+    pub const fn ctrl(code: KeyCode) -> Self {
+        Self::Single {
+            code,
+            modifiers: Modifiers::CTRL,
+        }
+    }
+
+    /// Convenience: g-prefix sequence (g + char).
+    #[must_use]
+    pub const fn g_then(c: char) -> Self {
+        Self::Sequence {
+            first_code: KeyCode::Char('g'),
+            first_modifiers: Modifiers::NONE,
+            second_code: KeyCode::Char(c),
+            second_modifiers: Modifiers::NONE,
+        }
+    }
+
+    /// Human-readable display string for this key combo.
+    #[must_use]
+    pub fn display(&self) -> String {
+        match self {
+            Self::Single { code, modifiers } => format_key(*code, *modifiers),
+            Self::Sequence {
+                first_code,
+                first_modifiers,
+                second_code,
+                second_modifiers,
+            } => {
+                let first = format_key(*first_code, *first_modifiers);
+                let second = format_key(*second_code, *second_modifiers);
+                format!("{first} {second}")
+            }
+        }
+    }
+
+    /// Whether this combo starts with the given key.
+    #[must_use]
+    pub fn starts_with(&self, code: &KeyCode, modifiers: &Modifiers) -> bool {
+        match self {
+            Self::Single {
+                code: c,
+                modifiers: m,
+            } => c == code && m == modifiers,
+            Self::Sequence {
+                first_code,
+                first_modifiers,
+                ..
+            } => first_code == code && first_modifiers == modifiers,
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// ScreenFilter
+// ---------------------------------------------------------------------------
+
+/// Specifies which screens a command is available on.
+#[derive(Debug, Clone)]
+pub enum ScreenFilter {
+    /// Available on all screens.
+    Global,
+    /// Available only on specific screens.
+    Only(Vec<Screen>),
+}
+
+impl ScreenFilter {
+    /// Whether the command is available on the given screen.
+    #[must_use]
+    pub fn matches(&self, screen: &Screen) -> bool {
+        match self {
+            Self::Global => true,
+            Self::Only(screens) => screens.contains(screen),
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// CommandDef
+// ---------------------------------------------------------------------------
+
+/// Unique command identifier.
+pub type CommandId = &'static str;
+
+/// A registered command with its keybinding, help text, and scope.
+#[derive(Debug, Clone)]
+pub struct CommandDef {
+    /// Unique identifier (e.g., "quit", "go_issues").
+    pub id: CommandId,
+    /// Human-readable label for palette and help overlay.
+    pub label: &'static str,
+    /// Keybinding (if any).
+    pub keybinding: Option<KeyCombo>,
+    /// Equivalent `lore` CLI command (for "Show CLI equivalent" feature).
+    pub cli_equivalent: Option<&'static str>,
+    /// Description for help overlay.
+    pub help_text: &'static str,
+    /// Short hint for status bar (e.g., "q:quit").
+    pub status_hint: &'static str,
+    /// Which screens this command is available on.
+    pub available_in: ScreenFilter,
+    /// Whether this command works in Text input mode.
+    pub available_in_text_mode: bool,
+}
+
+// ---------------------------------------------------------------------------
+// CommandRegistry
+// ---------------------------------------------------------------------------
+
+/// Single source of truth for all TUI commands.
+///
+/// Built once at startup via [`build_registry`]. Provides O(1) lookup
+/// by keybinding and per-screen filtering.
+pub struct CommandRegistry {
+    commands: Vec<CommandDef>,
+    /// Single-key -> command IDs that start with this key.
+    by_single_key: HashMap<(KeyCode, Modifiers), Vec<usize>>,
+    /// Full sequence -> command index (for two-key combos).
+    by_sequence: HashMap<KeyCombo, usize>,
+}
+
+impl CommandRegistry {
+    /// Look up a command by a single key press on a given screen and input mode.
+    ///
+    /// Returns `None` if no matching command is found. For sequence starters
+    /// (like 'g'), returns `None` — use [`is_sequence_starter`] to detect
+    /// that case.
+    #[must_use]
+    pub fn lookup_key(
+        &self,
+        code: &KeyCode,
+        modifiers: &Modifiers,
+        screen: &Screen,
+        mode: &InputMode,
+    ) -> Option<&CommandDef> {
+        let is_text = matches!(mode, InputMode::Text);
+        let key = (*code, *modifiers);
+
+        let indices = self.by_single_key.get(&key)?;
+        for &idx in indices {
+            let cmd = &self.commands[idx];
+            if !cmd.available_in.matches(screen) {
+                continue;
+            }
+            if is_text && !cmd.available_in_text_mode {
+                continue;
+            }
+            // Only match Single combos here, not sequence starters.
+            if let Some(KeyCombo::Single { .. }) = &cmd.keybinding {
+                return Some(cmd);
+            }
+        }
+        None
+    }
+
+    /// Complete a two-key sequence.
+    ///
+    /// Called after the first key of a sequence is detected (e.g., after 'g').
+    #[must_use]
+    pub fn complete_sequence(
+        &self,
+        first_code: &KeyCode,
+        first_modifiers: &Modifiers,
+        second_code: &KeyCode,
+        second_modifiers: &Modifiers,
+        screen: &Screen,
+    ) -> Option<&CommandDef> {
+        let combo = KeyCombo::Sequence {
+            first_code: *first_code,
+            first_modifiers: *first_modifiers,
+            second_code: *second_code,
+            second_modifiers: *second_modifiers,
+        };
+        let &idx = self.by_sequence.get(&combo)?;
+        let cmd = &self.commands[idx];
+        if cmd.available_in.matches(screen) {
+            Some(cmd)
+        } else {
+            None
+        }
+    }
+
+    /// Whether a key starts a multi-key sequence (e.g., 'g').
+    #[must_use]
+    pub fn is_sequence_starter(&self, code: &KeyCode, modifiers: &Modifiers) -> bool {
+        self.by_sequence
+            .keys()
+            .any(|combo| combo.starts_with(code, modifiers))
+    }
+
+    /// Commands available for the command palette on a given screen.
+    ///
+    /// Returned sorted by label.
+    #[must_use]
+    pub fn palette_entries(&self, screen: &Screen) -> Vec<&CommandDef> {
+        let mut entries: Vec<&CommandDef> = self
+            .commands
+            .iter()
+            .filter(|c| c.available_in.matches(screen))
+            .collect();
+        entries.sort_by_key(|c| c.label);
+        entries
+    }
+
+    /// Commands for the help overlay on a given screen.
+    #[must_use]
+    pub fn help_entries(&self, screen: &Screen) -> Vec<&CommandDef> {
+        self.commands
+            .iter()
+            .filter(|c| c.available_in.matches(screen))
+            .filter(|c| c.keybinding.is_some())
+            .collect()
+    }
+
+    /// Status bar hints for the current screen.
+    #[must_use]
+    pub fn status_hints(&self, screen: &Screen) -> Vec<&str> {
+        self.commands
+            .iter()
+            .filter(|c| c.available_in.matches(screen))
+            .filter(|c| !c.status_hint.is_empty())
+            .map(|c| c.status_hint)
+            .collect()
+    }
+
+    /// Total number of registered commands.
+    #[must_use]
+    pub fn len(&self) -> usize {
+        self.commands.len()
+    }
+
+    /// Whether the registry has no commands.
+    #[must_use]
+    pub fn is_empty(&self) -> bool {
+        self.commands.is_empty()
+    }
+}
+
+// ---------------------------------------------------------------------------
+// build_registry
+// ---------------------------------------------------------------------------
+
+/// Build the command registry with all TUI commands.
+///
+/// This is the single source of truth — every keybinding, help text,
+/// and palette entry originates here.
+#[must_use]
+pub fn build_registry() -> CommandRegistry {
+    let commands = vec![
+        // --- Global commands ---
+        CommandDef {
+            id: "quit",
+            label: "Quit",
+            keybinding: Some(KeyCombo::key(KeyCode::Char('q'))),
+            cli_equivalent: None,
+            help_text: "Exit the TUI",
+            status_hint: "q:quit",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "go_back",
+            label: "Go Back",
+            keybinding: Some(KeyCombo::key(KeyCode::Escape)),
+            cli_equivalent: None,
+            help_text: "Go back to previous screen",
+            status_hint: "esc:back",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: true,
+        },
+        CommandDef {
+            id: "show_help",
+            label: "Help",
+            keybinding: Some(KeyCombo::key(KeyCode::Char('?'))),
+            cli_equivalent: None,
+            help_text: "Show keybinding help overlay",
+            status_hint: "?:help",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "command_palette",
+            label: "Command Palette",
+            keybinding: Some(KeyCombo::ctrl(KeyCode::Char('p'))),
+            cli_equivalent: None,
+            help_text: "Open command palette",
+            status_hint: "C-p:palette",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: true,
+        },
+        CommandDef {
+            id: "open_in_browser",
+            label: "Open in Browser",
+            keybinding: Some(KeyCombo::key(KeyCode::Char('o'))),
+            cli_equivalent: None,
+            help_text: "Open current entity in browser",
+            status_hint: "o:browser",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "show_cli",
+            label: "Show CLI Equivalent",
+            keybinding: Some(KeyCombo::key(KeyCode::Char('!'))),
+            cli_equivalent: None,
+            help_text: "Show equivalent lore CLI command",
+            status_hint: "",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        // --- Navigation: g-prefix sequences ---
+        CommandDef {
+            id: "go_home",
+            label: "Go to Dashboard",
+            keybinding: Some(KeyCombo::g_then('h')),
+            cli_equivalent: None,
+            help_text: "Jump to dashboard",
+            status_hint: "gh:home",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "go_issues",
+            label: "Go to Issues",
+            keybinding: Some(KeyCombo::g_then('i')),
+            cli_equivalent: Some("lore issues"),
+            help_text: "Jump to issue list",
+            status_hint: "gi:issues",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "go_mrs",
+            label: "Go to Merge Requests",
+            keybinding: Some(KeyCombo::g_then('m')),
+            cli_equivalent: Some("lore mrs"),
+            help_text: "Jump to MR list",
+            status_hint: "gm:mrs",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "go_search",
+            label: "Go to Search",
+            keybinding: Some(KeyCombo::g_then('/')),
+            cli_equivalent: Some("lore search"),
+            help_text: "Jump to search",
+            status_hint: "g/:search",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "go_timeline",
+            label: "Go to Timeline",
+            keybinding: Some(KeyCombo::g_then('t')),
+            cli_equivalent: Some("lore timeline"),
+            help_text: "Jump to timeline",
+            status_hint: "gt:timeline",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "go_who",
+            label: "Go to Who",
+            keybinding: Some(KeyCombo::g_then('w')),
+            cli_equivalent: Some("lore who"),
+            help_text: "Jump to people intelligence",
+            status_hint: "gw:who",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "go_sync",
+            label: "Go to Sync",
+            keybinding: Some(KeyCombo::g_then('s')),
+            cli_equivalent: Some("lore sync"),
+            help_text: "Jump to sync status",
+            status_hint: "gs:sync",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        // --- Vim-style jump list ---
+        CommandDef {
+            id: "jump_back",
+            label: "Jump Back",
+            keybinding: Some(KeyCombo::ctrl(KeyCode::Char('o'))),
+            cli_equivalent: None,
+            help_text: "Jump backward through visited detail views",
+            status_hint: "C-o:jump back",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "jump_forward",
+            label: "Jump Forward",
+            keybinding: Some(KeyCombo::ctrl(KeyCode::Char('i'))),
+            cli_equivalent: None,
+            help_text: "Jump forward through visited detail views",
+            status_hint: "",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+        // --- List navigation ---
+        CommandDef {
+            id: "move_down",
+            label: "Move Down",
+            keybinding: Some(KeyCombo::key(KeyCode::Char('j'))),
+            cli_equivalent: None,
+            help_text: "Move cursor down",
+            status_hint: "j:down",
+            available_in: ScreenFilter::Only(vec![
+                Screen::IssueList,
+                Screen::MrList,
+                Screen::Search,
+                Screen::Timeline,
+            ]),
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "move_up",
+            label: "Move Up",
+            keybinding: Some(KeyCombo::key(KeyCode::Char('k'))),
+            cli_equivalent: None,
+            help_text: "Move cursor up",
+            status_hint: "k:up",
+            available_in: ScreenFilter::Only(vec![
+                Screen::IssueList,
+                Screen::MrList,
+                Screen::Search,
+                Screen::Timeline,
+            ]),
+            available_in_text_mode: false,
+        },
+        CommandDef {
+            id: "select_item",
+            label: "Select",
+            keybinding: Some(KeyCombo::key(KeyCode::Enter)),
+            cli_equivalent: None,
+            help_text: "Open selected item",
+            status_hint: "enter:open",
+            available_in: ScreenFilter::Only(vec![
+                Screen::IssueList,
+                Screen::MrList,
+                Screen::Search,
+            ]),
+            available_in_text_mode: false,
+        },
+        // --- Filter ---
+        CommandDef {
+            id: "focus_filter",
+            label: "Filter",
+            keybinding: Some(KeyCombo::key(KeyCode::Char('/'))),
+            cli_equivalent: None,
+            help_text: "Focus the filter input",
+            status_hint: "/:filter",
+            available_in: ScreenFilter::Only(vec![Screen::IssueList, Screen::MrList]),
+            available_in_text_mode: false,
+        },
+        // --- Scroll ---
+        CommandDef {
+            id: "scroll_to_top",
+            label: "Scroll to Top",
+            keybinding: Some(KeyCombo::g_then('g')),
+            cli_equivalent: None,
+            help_text: "Scroll to the top of the current view",
+            status_hint: "",
+            available_in: ScreenFilter::Global,
+            available_in_text_mode: false,
+        },
+    ];
+
+    build_from_defs(commands)
+}
+
+/// Build index maps from a list of command definitions.
+fn build_from_defs(commands: Vec<CommandDef>) -> CommandRegistry {
+    let mut by_single_key: HashMap<(KeyCode, Modifiers), Vec<usize>> = HashMap::new();
+    let mut by_sequence: HashMap<KeyCombo, usize> = HashMap::new();
+
+    for (idx, cmd) in commands.iter().enumerate() {
+        if let Some(combo) = &cmd.keybinding {
+            match combo {
+                KeyCombo::Single { code, modifiers } => {
+                    by_single_key
+                        .entry((*code, *modifiers))
+                        .or_default()
+                        .push(idx);
+                }
+                KeyCombo::Sequence { .. } => {
+                    by_sequence.insert(combo.clone(), idx);
+                    // Also index the first key so is_sequence_starter works via by_single_key.
+                    if let KeyCombo::Sequence {
+                        first_code,
+                        first_modifiers,
+                        ..
+                    } = combo
+                    {
+                        by_single_key
+                            .entry((*first_code, *first_modifiers))
+                            .or_default()
+                            .push(idx);
+                    }
+                }
+            }
+        }
+    }
+
+    CommandRegistry {
+        commands,
+        by_single_key,
+        by_sequence,
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::Utc;
+
+    #[test]
+    fn test_registry_builds_successfully() {
+        let reg = build_registry();
+        assert!(!reg.is_empty());
+        assert!(reg.len() >= 15);
+    }
+
+    #[test]
+    fn test_registry_lookup_quit() {
+        let reg = build_registry();
+        let cmd = reg.lookup_key(
+            &KeyCode::Char('q'),
+            &Modifiers::NONE,
+            &Screen::Dashboard,
+            &InputMode::Normal,
+        );
+        assert!(cmd.is_some());
+        assert_eq!(cmd.unwrap().id, "quit");
+    }
+
+    #[test]
+    fn test_registry_lookup_quit_blocked_in_text_mode() {
+        let reg = build_registry();
+        let cmd = reg.lookup_key(
+            &KeyCode::Char('q'),
+            &Modifiers::NONE,
+            &Screen::Dashboard,
+            &InputMode::Text,
+        );
+        assert!(cmd.is_none());
+    }
+
+    #[test]
+    fn test_registry_esc_works_in_text_mode() {
+        let reg = build_registry();
+        let cmd = reg.lookup_key(
+            &KeyCode::Escape,
+            &Modifiers::NONE,
+            &Screen::IssueList,
+            &InputMode::Text,
+        );
+        assert!(cmd.is_some());
+        assert_eq!(cmd.unwrap().id, "go_back");
+    }
+
+    #[test]
+    fn test_registry_ctrl_p_works_in_text_mode() {
+        let reg = build_registry();
+        let cmd = reg.lookup_key(
+            &KeyCode::Char('p'),
+            &Modifiers::CTRL,
+            &Screen::Search,
+            &InputMode::Text,
+        );
+        assert!(cmd.is_some());
+        assert_eq!(cmd.unwrap().id, "command_palette");
+    }
+
+    #[test]
+    fn test_g_is_sequence_starter() {
+        let reg = build_registry();
+        assert!(reg.is_sequence_starter(&KeyCode::Char('g'), &Modifiers::NONE));
+        assert!(!reg.is_sequence_starter(&KeyCode::Char('x'), &Modifiers::NONE));
+    }
+
+    #[test]
+    fn test_complete_sequence_gi() {
+        let reg = build_registry();
+        let cmd = reg.complete_sequence(
+            &KeyCode::Char('g'),
+            &Modifiers::NONE,
+            &KeyCode::Char('i'),
+            &Modifiers::NONE,
+            &Screen::Dashboard,
+        );
+        assert!(cmd.is_some());
+        assert_eq!(cmd.unwrap().id, "go_issues");
+    }
+
+    #[test]
+    fn test_complete_sequence_invalid_second_key() {
+        let reg = build_registry();
+        let cmd = reg.complete_sequence(
+            &KeyCode::Char('g'),
+            &Modifiers::NONE,
+            &KeyCode::Char('x'),
+            &Modifiers::NONE,
+            &Screen::Dashboard,
+        );
+        assert!(cmd.is_none());
+    }
+
+    #[test]
+    fn test_screen_specific_command() {
+        let reg = build_registry();
+        // 'j' (move_down) should work on IssueList
+        let cmd = reg.lookup_key(
+            &KeyCode::Char('j'),
+            &Modifiers::NONE,
+            &Screen::IssueList,
+            &InputMode::Normal,
+        );
+        assert!(cmd.is_some());
+        assert_eq!(cmd.unwrap().id, "move_down");
+
+        // 'j' should NOT match on Dashboard (move_down is list-only).
+        let cmd = reg.lookup_key(
+            &KeyCode::Char('j'),
+            &Modifiers::NONE,
+            &Screen::Dashboard,
+            &InputMode::Normal,
+        );
+        assert!(cmd.is_none());
+    }
+
+    #[test]
+    fn test_palette_entries_sorted_by_label() {
+        let reg = build_registry();
+        let entries = reg.palette_entries(&Screen::Dashboard);
+        let labels: Vec<&str> = entries.iter().map(|c| c.label).collect();
+        let mut sorted = labels.clone();
+        sorted.sort();
+        assert_eq!(labels, sorted);
+    }
+
+    #[test]
+    fn test_help_entries_only_include_keybindings() {
+        let reg = build_registry();
+        let entries = reg.help_entries(&Screen::Dashboard);
+        for entry in &entries {
+            assert!(
+                entry.keybinding.is_some(),
+                "help entry without keybinding: {}",
+                entry.id
+            );
+        }
+    }
+
+    #[test]
+    fn test_status_hints_non_empty() {
+        let reg = build_registry();
+        let hints = reg.status_hints(&Screen::Dashboard);
+        assert!(!hints.is_empty());
+        // All returned hints should be non-empty strings.
+        for hint in &hints {
+            assert!(!hint.is_empty());
+        }
+    }
+
+    #[test]
+    fn test_cli_equivalents_populated() {
+        let reg = build_registry();
+        let with_cli: Vec<&CommandDef> = reg
+            .commands
+            .iter()
+            .filter(|c| c.cli_equivalent.is_some())
+            .collect();
+        assert!(
+            with_cli.len() >= 5,
+            "expected at least 5 commands with cli_equivalent, got {}",
+            with_cli.len()
+        );
+    }
+
+    #[test]
+    fn test_go_prefix_timeout_detection() {
+        let reg = build_registry();
+        // Simulate GoPrefix mode entering: 'g' detected as sequence starter.
+        assert!(reg.is_sequence_starter(&KeyCode::Char('g'), &Modifiers::NONE));
+
+        // Simulate InputMode::GoPrefix with timeout check.
+        let started = Utc::now();
+        let mode = InputMode::GoPrefix {
+            started_at: started,
+        };
+        // In GoPrefix mode, normal lookup should still work for non-sequence keys.
+        let cmd = reg.lookup_key(
+            &KeyCode::Char('q'),
+            &Modifiers::NONE,
+            &Screen::Dashboard,
+            &mode,
+        );
+        assert!(cmd.is_some());
+        assert_eq!(cmd.unwrap().id, "quit");
+    }
+
+    #[test]
+    fn test_all_commands_have_nonempty_help() {
+        let reg = build_registry();
+        for cmd in &reg.commands {
+            assert!(
+                !cmd.help_text.is_empty(),
+                "command {} has empty help_text",
+                cmd.id
+            );
+        }
+    }
+}

crates/lore-tui/src/crash_context.rs

@@ -0,0 +1,443 @@
+#![allow(dead_code)] // Phase 1: consumed by LoreApp in bd-6pmy
+
+//! Ring buffer of recent app events for post-mortem crash diagnostics.
+//!
+//! The TUI pushes every key press, message dispatch, and state transition
+//! into [`CrashContext`]. On panic the installed hook dumps the last 2000
+//! events to `~/.local/share/lore/crash-<timestamp>.json` as NDJSON.
+//!
+//! Retention: only the 5 most recent crash files are kept.
+
+use std::collections::VecDeque;
+use std::io::{self, BufWriter, Write};
+use std::path::{Path, PathBuf};
+
+use serde::Serialize;
+
+/// Maximum number of events retained in the ring buffer.
+const MAX_EVENTS: usize = 2000;
+
+/// Maximum number of crash files to keep on disk.
+const MAX_CRASH_FILES: usize = 5;
+
+// ---------------------------------------------------------------------------
+// CrashEvent
+// ---------------------------------------------------------------------------
+
+/// A single event recorded for crash diagnostics.
+#[derive(Debug, Clone, Serialize)]
+#[serde(tag = "type")]
+pub enum CrashEvent {
+    /// A key was pressed.
+    KeyPress {
+        key: String,
+        mode: String,
+        screen: String,
+    },
+    /// A message was dispatched through update().
+    MsgDispatched { msg_name: String, screen: String },
+    /// Navigation changed screens.
+    StateTransition { from: String, to: String },
+    /// An error occurred.
+    Error { message: String },
+    /// Catch-all for ad-hoc diagnostic breadcrumbs.
+    Custom { tag: String, detail: String },
+}
+
+// ---------------------------------------------------------------------------
+// CrashContext
+// ---------------------------------------------------------------------------
+
+/// Ring buffer of recent app events for panic diagnostics.
+///
+/// Holds at most [`MAX_EVENTS`] entries. When full, the oldest event
+/// is evicted on each push.
+pub struct CrashContext {
+    events: VecDeque<CrashEvent>,
+}
+
+impl CrashContext {
+    /// Create an empty crash context with pre-allocated capacity.
+    #[must_use]
+    pub fn new() -> Self {
+        Self {
+            events: VecDeque::with_capacity(MAX_EVENTS),
+        }
+    }
+
+    /// Record an event. Evicts the oldest when the buffer is full.
+    pub fn push(&mut self, event: CrashEvent) {
+        if self.events.len() == MAX_EVENTS {
+            self.events.pop_front();
+        }
+        self.events.push_back(event);
+    }
+
+    /// Number of events currently stored.
+    #[must_use]
+    pub fn len(&self) -> usize {
+        self.events.len()
+    }
+
+    /// Whether the buffer is empty.
+    #[must_use]
+    pub fn is_empty(&self) -> bool {
+        self.events.is_empty()
+    }
+
+    /// Iterate over stored events (oldest first).
+    pub fn iter(&self) -> impl Iterator<Item = &CrashEvent> {
+        self.events.iter()
+    }
+
+    /// Dump all events to a file as newline-delimited JSON.
+    ///
+    /// Creates parent directories if they don't exist.
+    /// Returns `Ok(())` on success, `Err` on I/O failure.
+    pub fn dump_to_file(&self, path: &Path) -> io::Result<()> {
+        if let Some(parent) = path.parent() {
+            std::fs::create_dir_all(parent)?;
+        }
+        let file = std::fs::File::create(path)?;
+        let mut writer = BufWriter::new(file);
+        for event in &self.events {
+            match serde_json::to_string(event) {
+                Ok(json) => {
+                    writeln!(writer, "{json}")?;
+                }
+                Err(_) => {
+                    // Fallback to debug format if serialization fails.
+                    writeln!(
+                        writer,
+                        "{{\"type\":\"SerializationError\",\"debug\":\"{event:?}\"}}"
+                    )?;
+                }
+            }
+        }
+        writer.flush()?;
+        Ok(())
+    }
+
+    /// Default crash directory: `~/.local/share/lore/`.
+    #[must_use]
+    pub fn crash_dir() -> Option<PathBuf> {
+        dirs::data_local_dir().map(|d| d.join("lore"))
+    }
+
+    /// Generate a timestamped crash file path.
+    #[must_use]
+    pub fn crash_file_path() -> Option<PathBuf> {
+        let dir = Self::crash_dir()?;
+        let timestamp = chrono::Utc::now().format("%Y%m%d-%H%M%S%.3f");
+        Some(dir.join(format!("crash-{timestamp}.json")))
+    }
+
+    /// Remove old crash files, keeping only the most recent [`MAX_CRASH_FILES`].
+    ///
+    /// Best-effort: silently ignores I/O errors on individual deletions.
+    pub fn prune_crash_files() {
+        let Some(dir) = Self::crash_dir() else {
+            return;
+        };
+        let Ok(entries) = std::fs::read_dir(&dir) else {
+            return;
+        };
+
+        let mut crash_files: Vec<PathBuf> = entries
+            .filter_map(Result::ok)
+            .map(|e| e.path())
+            .filter(|p| {
+                p.file_name()
+                    .and_then(|n| n.to_str())
+                    .is_some_and(|n| n.starts_with("crash-") && n.ends_with(".json"))
+            })
+            .collect();
+
+        // Sort ascending by filename (timestamps sort lexicographically).
+        crash_files.sort();
+
+        if crash_files.len() > MAX_CRASH_FILES {
+            let to_remove = crash_files.len() - MAX_CRASH_FILES;
+            for path in &crash_files[..to_remove] {
+                let _ = std::fs::remove_file(path);
+            }
+        }
+    }
+
+    /// Install a panic hook that dumps the crash context to disk.
+    ///
+    /// Captures the current events via a snapshot. The hook chains with
+    /// the default panic handler so backtraces are still printed.
+    pub fn install_panic_hook(ctx: &Self) {
+        let snapshot: Vec<CrashEvent> = ctx.events.iter().cloned().collect();
+        let prev_hook = std::panic::take_hook();
+
+        std::panic::set_hook(Box::new(move |info| {
+            // Best-effort dump — never panic inside the panic hook.
+            if let Some(path) = Self::crash_file_path() {
+                let mut dump = CrashContext::new();
+                for event in &snapshot {
+                    dump.push(event.clone());
+                }
+                // Add the panic info itself as the final event.
+                dump.push(CrashEvent::Error {
+                    message: format!("{info}"),
+                });
+                let _ = dump.dump_to_file(&path);
+            }
+
+            // Chain to the previous hook (prints backtrace, etc.).
+            prev_hook(info);
+        }));
+    }
+}
+
+impl Default for CrashContext {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::io::BufRead;
+
+    /// Helper: create a numbered Custom event.
+    fn event(n: usize) -> CrashEvent {
+        CrashEvent::Custom {
+            tag: "test".into(),
+            detail: format!("event-{n}"),
+        }
+    }
+
+    #[test]
+    fn test_ring_buffer_evicts_oldest() {
+        let mut ctx = CrashContext::new();
+        for i in 0..2500 {
+            ctx.push(event(i));
+        }
+        assert_eq!(ctx.len(), MAX_EVENTS);
+
+        // First retained event should be #500 (0..499 evicted).
+        let first = ctx.iter().next().unwrap();
+        match first {
+            CrashEvent::Custom { detail, .. } => assert_eq!(detail, "event-500"),
+            other => panic!("unexpected variant: {other:?}"),
+        }
+
+        // Last retained event should be #2499.
+        let last = ctx.iter().last().unwrap();
+        match last {
+            CrashEvent::Custom { detail, .. } => assert_eq!(detail, "event-2499"),
+            other => panic!("unexpected variant: {other:?}"),
+        }
+    }
+
+    #[test]
+    fn test_new_is_empty() {
+        let ctx = CrashContext::new();
+        assert!(ctx.is_empty());
+        assert_eq!(ctx.len(), 0);
+    }
+
+    #[test]
+    fn test_push_increments_len() {
+        let mut ctx = CrashContext::new();
+        ctx.push(event(1));
+        ctx.push(event(2));
+        assert_eq!(ctx.len(), 2);
+    }
+
+    #[test]
+    fn test_push_does_not_evict_below_capacity() {
+        let mut ctx = CrashContext::new();
+        for i in 0..MAX_EVENTS {
+            ctx.push(event(i));
+        }
+        assert_eq!(ctx.len(), MAX_EVENTS);
+
+        // First should still be event-0.
+        match ctx.iter().next().unwrap() {
+            CrashEvent::Custom { detail, .. } => assert_eq!(detail, "event-0"),
+            other => panic!("unexpected: {other:?}"),
+        }
+    }
+
+    #[test]
+    fn test_dump_to_file_writes_ndjson() {
+        let mut ctx = CrashContext::new();
+        ctx.push(CrashEvent::KeyPress {
+            key: "j".into(),
+            mode: "Normal".into(),
+            screen: "Dashboard".into(),
+        });
+        ctx.push(CrashEvent::MsgDispatched {
+            msg_name: "NavigateTo".into(),
+            screen: "Dashboard".into(),
+        });
+        ctx.push(CrashEvent::StateTransition {
+            from: "Dashboard".into(),
+            to: "IssueList".into(),
+        });
+        ctx.push(CrashEvent::Error {
+            message: "db busy".into(),
+        });
+        ctx.push(CrashEvent::Custom {
+            tag: "test".into(),
+            detail: "hello".into(),
+        });
+
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("test-crash.json");
+        ctx.dump_to_file(&path).unwrap();
+
+        // Verify: each line is valid JSON, total lines == 5.
+        let file = std::fs::File::open(&path).unwrap();
+        let reader = io::BufReader::new(file);
+        let lines: Vec<String> = reader.lines().map(Result::unwrap).collect();
+        assert_eq!(lines.len(), 5);
+
+        // Each line must parse as JSON.
+        for line in &lines {
+            let val: serde_json::Value = serde_json::from_str(line).unwrap();
+            assert!(val.get("type").is_some(), "missing 'type' field: {line}");
+        }
+
+        // Spot check first line: KeyPress with correct fields.
+        let first: serde_json::Value = serde_json::from_str(&lines[0]).unwrap();
+        assert_eq!(first["type"], "KeyPress");
+        assert_eq!(first["key"], "j");
+        assert_eq!(first["mode"], "Normal");
+        assert_eq!(first["screen"], "Dashboard");
+    }
+
+    #[test]
+    fn test_dump_creates_parent_directories() {
+        let dir = tempfile::tempdir().unwrap();
+        let nested = dir.path().join("a").join("b").join("c").join("crash.json");
+
+        let mut ctx = CrashContext::new();
+        ctx.push(event(1));
+        ctx.dump_to_file(&nested).unwrap();
+
+        assert!(nested.exists());
+    }
+
+    #[test]
+    fn test_dump_empty_context_creates_empty_file() {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("empty.json");
+
+        let ctx = CrashContext::new();
+        ctx.dump_to_file(&path).unwrap();
+
+        let content = std::fs::read_to_string(&path).unwrap();
+        assert!(content.is_empty());
+    }
+
+    #[test]
+    fn test_prune_keeps_newest_files() {
+        let dir = tempfile::tempdir().unwrap();
+        let crash_dir = dir.path();
+
+        // Create 8 crash files with ordered timestamps.
+        let filenames: Vec<String> = (0..8)
+            .map(|i| format!("crash-2026010{i}-120000.000.json"))
+            .collect();
+        for name in &filenames {
+            std::fs::write(crash_dir.join(name), "{}").unwrap();
+        }
+
+        // Prune, pointing at our temp dir.
+        prune_crash_files_in(crash_dir);
+
+        let remaining: Vec<String> = std::fs::read_dir(crash_dir)
+            .unwrap()
+            .filter_map(Result::ok)
+            .map(|e| e.file_name().to_string_lossy().into_owned())
+            .filter(|n| n.starts_with("crash-") && n.ends_with(".json"))
+            .collect();
+
+        assert_eq!(remaining.len(), MAX_CRASH_FILES);
+        // Oldest 3 should be gone.
+        for name in filenames.iter().take(3) {
+            assert!(!remaining.contains(name));
+        }
+        // Newest 5 should remain.
+        for name in filenames.iter().skip(3) {
+            assert!(remaining.contains(name));
+        }
+    }
+
+    #[test]
+    fn test_all_event_variants_serialize() {
+        let events = vec![
+            CrashEvent::KeyPress {
+                key: "q".into(),
+                mode: "Normal".into(),
+                screen: "Dashboard".into(),
+            },
+            CrashEvent::MsgDispatched {
+                msg_name: "Quit".into(),
+                screen: "Dashboard".into(),
+            },
+            CrashEvent::StateTransition {
+                from: "Dashboard".into(),
+                to: "IssueList".into(),
+            },
+            CrashEvent::Error {
+                message: "oops".into(),
+            },
+            CrashEvent::Custom {
+                tag: "debug".into(),
+                detail: "trace".into(),
+            },
+        ];
+
+        for event in events {
+            let json = serde_json::to_string(&event).unwrap();
+            let parsed: serde_json::Value = serde_json::from_str(&json).unwrap();
+            assert!(parsed.get("type").is_some());
+        }
+    }
+
+    #[test]
+    fn test_default_is_new() {
+        let ctx = CrashContext::default();
+        assert!(ctx.is_empty());
+    }
+
+    // -----------------------------------------------------------------------
+    // Test helper: prune files in a specific directory (not the real path).
+    // -----------------------------------------------------------------------
+
+    fn prune_crash_files_in(dir: &Path) {
+        let Ok(entries) = std::fs::read_dir(dir) else {
+            return;
+        };
+
+        let mut crash_files: Vec<PathBuf> = entries
+            .filter_map(Result::ok)
+            .map(|e| e.path())
+            .filter(|p| {
+                p.file_name()
+                    .and_then(|n| n.to_str())
+                    .is_some_and(|n| n.starts_with("crash-") && n.ends_with(".json"))
+            })
+            .collect();
+
+        crash_files.sort();
+
+        if crash_files.len() > MAX_CRASH_FILES {
+            let to_remove = crash_files.len() - MAX_CRASH_FILES;
+            for path in &crash_files[..to_remove] {
+                let _ = std::fs::remove_file(path);
+            }
+        }
+    }
+}

crates/lore-tui/src/lib.rs

@@ -18,6 +18,14 @@ pub mod theme; // Flexoki theme: build_theme, state_color, label_style (bd-5ofk)
 
 pub mod app; // LoreApp Model trait impl (Phase 0 proof: bd-2emv, full: bd-6pmy)
 
+// Phase 1 modules.
+pub mod commands; // CommandRegistry: keybindings, help, palette (bd-38lb)
+pub mod crash_context; // CrashContext ring buffer + panic hook (bd-2fr7)
+pub mod navigation; // NavigationStack: back/forward/jump list (bd-1qpp)
+pub mod state; // AppState, LoadState, ScreenIntent, per-screen states (bd-1v9m)
+pub mod task_supervisor; // TaskSupervisor: dedup + cancel + generation IDs (bd-3le2)
+pub mod view; // View layer: render_screen + common widgets (bd-26f2)
+
 /// Options controlling how the TUI launches.
 #[derive(Debug, Clone)]
 pub struct LaunchOptions {

crates/lore-tui/src/message.rs

@@ -9,8 +9,8 @@
 //! - [`InputMode`] — controls key dispatch routing.
 
 use std::fmt;
-use std::time::Instant;
 
+use chrono::{DateTime, Utc};
 use ftui::Event;
 
 // ---------------------------------------------------------------------------
@@ -74,7 +74,7 @@ impl fmt::Display for EntityKey {
 // ---------------------------------------------------------------------------
 
 /// Navigation targets within the TUI.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum Screen {
     Dashboard,
     IssueList,
@@ -174,7 +174,7 @@ pub enum InputMode {
     /// Command palette is open.
     Palette,
     /// "g" prefix pressed — waiting for second key (500ms timeout).
-    GoPrefix { started_at: Instant },
+    GoPrefix { started_at: DateTime<Utc> },
 }
 
 // ---------------------------------------------------------------------------

crates/lore-tui/src/navigation.rs

@@ -0,0 +1,339 @@
+#![allow(dead_code)] // Phase 1: consumed by LoreApp in bd-6pmy
+
+//! Browser-like navigation stack with vim-style jump list.
+//!
+//! Supports back/forward (browser), jump back/forward (vim Ctrl+O/Ctrl+I),
+//! and breadcrumb generation. State is preserved when navigating away —
+//! screens are never cleared on pop.
+
+use crate::message::Screen;
+
+// ---------------------------------------------------------------------------
+// NavigationStack
+// ---------------------------------------------------------------------------
+
+/// Browser-like navigation with back/forward stacks and a vim jump list.
+///
+/// The jump list only records "significant" hops — detail views and
+/// cross-references — skipping list/dashboard screens that users
+/// visit briefly during drilling.
+pub struct NavigationStack {
+    back_stack: Vec<Screen>,
+    current: Screen,
+    forward_stack: Vec<Screen>,
+    jump_list: Vec<Screen>,
+    jump_index: usize,
+}
+
+impl NavigationStack {
+    /// Create a new stack starting at the Dashboard.
+    #[must_use]
+    pub fn new() -> Self {
+        Self {
+            back_stack: Vec::new(),
+            current: Screen::Dashboard,
+            forward_stack: Vec::new(),
+            jump_list: Vec::new(),
+            jump_index: 0,
+        }
+    }
+
+    /// The currently displayed screen.
+    #[must_use]
+    pub fn current(&self) -> &Screen {
+        &self.current
+    }
+
+    /// Whether the current screen matches the given screen.
+    #[must_use]
+    pub fn is_at(&self, screen: &Screen) -> bool {
+        &self.current == screen
+    }
+
+    /// Navigate to a new screen.
+    ///
+    /// Pushes current to back_stack, clears forward_stack (browser behavior),
+    /// and records detail hops in the jump list.
+    pub fn push(&mut self, screen: Screen) {
+        let old = std::mem::replace(&mut self.current, screen);
+        self.back_stack.push(old);
+        self.forward_stack.clear();
+
+        // Record significant hops in jump list (vim behavior):
+        // truncate any forward entries beyond jump_index, then append.
+        if self.current.is_detail_or_entity() {
+            self.jump_list.truncate(self.jump_index);
+            self.jump_list.push(self.current.clone());
+            self.jump_index = self.jump_list.len();
+        }
+    }
+
+    /// Go back to the previous screen.
+    ///
+    /// Returns `None` at root (can't pop past the initial screen).
+    pub fn pop(&mut self) -> Option<&Screen> {
+        let prev = self.back_stack.pop()?;
+        let old = std::mem::replace(&mut self.current, prev);
+        self.forward_stack.push(old);
+        Some(&self.current)
+    }
+
+    /// Go forward (redo a pop).
+    ///
+    /// Returns `None` if there's nothing to go forward to.
+    pub fn go_forward(&mut self) -> Option<&Screen> {
+        let next = self.forward_stack.pop()?;
+        let old = std::mem::replace(&mut self.current, next);
+        self.back_stack.push(old);
+        Some(&self.current)
+    }
+
+    /// Jump backward through the jump list (vim Ctrl+O).
+    ///
+    /// Only visits detail/entity screens.
+    pub fn jump_back(&mut self) -> Option<&Screen> {
+        if self.jump_index == 0 {
+            return None;
+        }
+        self.jump_index -= 1;
+        self.jump_list.get(self.jump_index)
+    }
+
+    /// Jump forward through the jump list (vim Ctrl+I).
+    pub fn jump_forward(&mut self) -> Option<&Screen> {
+        if self.jump_index >= self.jump_list.len() {
+            return None;
+        }
+        let screen = self.jump_list.get(self.jump_index)?;
+        self.jump_index += 1;
+        Some(screen)
+    }
+
+    /// Reset to a single screen, clearing all history.
+    pub fn reset_to(&mut self, screen: Screen) {
+        self.current = screen;
+        self.back_stack.clear();
+        self.forward_stack.clear();
+        self.jump_list.clear();
+        self.jump_index = 0;
+    }
+
+    /// Breadcrumb labels for the current navigation path.
+    ///
+    /// Returns the back stack labels plus the current screen label.
+    #[must_use]
+    pub fn breadcrumbs(&self) -> Vec<&str> {
+        self.back_stack
+            .iter()
+            .chain(std::iter::once(&self.current))
+            .map(Screen::label)
+            .collect()
+    }
+
+    /// Navigation depth (1 = at root, 2 = one push deep, etc.).
+    #[must_use]
+    pub fn depth(&self) -> usize {
+        self.back_stack.len() + 1
+    }
+
+    /// Whether there's anything to go back to.
+    #[must_use]
+    pub fn can_go_back(&self) -> bool {
+        !self.back_stack.is_empty()
+    }
+
+    /// Whether there's anything to go forward to.
+    #[must_use]
+    pub fn can_go_forward(&self) -> bool {
+        !self.forward_stack.is_empty()
+    }
+}
+
+impl Default for NavigationStack {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::message::EntityKey;
+
+    #[test]
+    fn test_new_starts_at_dashboard() {
+        let nav = NavigationStack::new();
+        assert!(nav.is_at(&Screen::Dashboard));
+        assert_eq!(nav.depth(), 1);
+    }
+
+    #[test]
+    fn test_push_pop_preserves_order() {
+        let mut nav = NavigationStack::new();
+        nav.push(Screen::IssueList);
+        nav.push(Screen::IssueDetail(EntityKey::issue(1, 42)));
+
+        assert!(nav.is_at(&Screen::IssueDetail(EntityKey::issue(1, 42))));
+        assert_eq!(nav.depth(), 3);
+
+        nav.pop();
+        assert!(nav.is_at(&Screen::IssueList));
+
+        nav.pop();
+        assert!(nav.is_at(&Screen::Dashboard));
+    }
+
+    #[test]
+    fn test_pop_at_root_returns_none() {
+        let mut nav = NavigationStack::new();
+        assert!(nav.pop().is_none());
+        assert!(nav.is_at(&Screen::Dashboard));
+    }
+
+    #[test]
+    fn test_forward_stack_cleared_on_new_push() {
+        let mut nav = NavigationStack::new();
+        nav.push(Screen::IssueList);
+        nav.push(Screen::Search);
+        nav.pop(); // back to IssueList, Search in forward
+        assert!(nav.can_go_forward());
+
+        nav.push(Screen::Timeline); // new push clears forward
+        assert!(!nav.can_go_forward());
+    }
+
+    #[test]
+    fn test_go_forward_restores() {
+        let mut nav = NavigationStack::new();
+        nav.push(Screen::IssueList);
+        nav.push(Screen::Search);
+        nav.pop(); // back to IssueList
+
+        let screen = nav.go_forward();
+        assert!(screen.is_some());
+        assert!(nav.is_at(&Screen::Search));
+    }
+
+    #[test]
+    fn test_go_forward_returns_none_when_empty() {
+        let mut nav = NavigationStack::new();
+        assert!(nav.go_forward().is_none());
+    }
+
+    #[test]
+    fn test_jump_list_skips_list_screens() {
+        let mut nav = NavigationStack::new();
+        nav.push(Screen::IssueList); // not a detail — skip
+        nav.push(Screen::IssueDetail(EntityKey::issue(1, 1))); // detail — record
+        nav.push(Screen::MrList); // not a detail — skip
+        nav.push(Screen::MrDetail(EntityKey::mr(1, 2))); // detail — record
+
+        assert_eq!(nav.jump_list.len(), 2);
+    }
+
+    #[test]
+    fn test_jump_back_and_forward() {
+        let mut nav = NavigationStack::new();
+        let issue = Screen::IssueDetail(EntityKey::issue(1, 1));
+        let mr = Screen::MrDetail(EntityKey::mr(1, 2));
+
+        nav.push(Screen::IssueList);
+        nav.push(issue.clone());
+        nav.push(Screen::MrList);
+        nav.push(mr.clone());
+
+        // jump_index is at 2 (past the end of 2 items)
+        let prev = nav.jump_back();
+        assert_eq!(prev, Some(&mr));
+
+        let prev = nav.jump_back();
+        assert_eq!(prev, Some(&issue));
+
+        // at beginning
+        assert!(nav.jump_back().is_none());
+
+        // forward
+        let next = nav.jump_forward();
+        assert_eq!(next, Some(&issue));
+
+        let next = nav.jump_forward();
+        assert_eq!(next, Some(&mr));
+
+        // at end
+        assert!(nav.jump_forward().is_none());
+    }
+
+    #[test]
+    fn test_jump_list_truncates_on_new_push() {
+        let mut nav = NavigationStack::new();
+        nav.push(Screen::IssueDetail(EntityKey::issue(1, 1)));
+        nav.push(Screen::IssueDetail(EntityKey::issue(1, 2)));
+        nav.push(Screen::IssueDetail(EntityKey::issue(1, 3)));
+
+        // jump back twice
+        nav.jump_back();
+        nav.jump_back();
+        // jump_index = 1, pointing at issue 2
+
+        // new detail push truncates forward entries
+        nav.push(Screen::MrDetail(EntityKey::mr(1, 99)));
+
+        // should have issue(1,1) and mr(1,99), not issue(1,2) or issue(1,3)
+        assert_eq!(nav.jump_list.len(), 2);
+        assert_eq!(nav.jump_list[1], Screen::MrDetail(EntityKey::mr(1, 99)));
+    }
+
+    #[test]
+    fn test_reset_clears_all_history() {
+        let mut nav = NavigationStack::new();
+        nav.push(Screen::IssueList);
+        nav.push(Screen::Search);
+        nav.push(Screen::IssueDetail(EntityKey::issue(1, 1)));
+
+        nav.reset_to(Screen::Dashboard);
+
+        assert!(nav.is_at(&Screen::Dashboard));
+        assert_eq!(nav.depth(), 1);
+        assert!(!nav.can_go_back());
+        assert!(!nav.can_go_forward());
+        assert!(nav.jump_list.is_empty());
+    }
+
+    #[test]
+    fn test_breadcrumbs_reflect_stack() {
+        let mut nav = NavigationStack::new();
+        assert_eq!(nav.breadcrumbs(), vec!["Dashboard"]);
+
+        nav.push(Screen::IssueList);
+        assert_eq!(nav.breadcrumbs(), vec!["Dashboard", "Issues"]);
+
+        nav.push(Screen::IssueDetail(EntityKey::issue(1, 42)));
+        assert_eq!(nav.breadcrumbs(), vec!["Dashboard", "Issues", "Issue"]);
+    }
+
+    #[test]
+    fn test_default_is_new() {
+        let nav = NavigationStack::default();
+        assert!(nav.is_at(&Screen::Dashboard));
+        assert_eq!(nav.depth(), 1);
+    }
+
+    #[test]
+    fn test_can_go_back_and_forward() {
+        let mut nav = NavigationStack::new();
+        assert!(!nav.can_go_back());
+        assert!(!nav.can_go_forward());
+
+        nav.push(Screen::IssueList);
+        assert!(nav.can_go_back());
+        assert!(!nav.can_go_forward());
+
+        nav.pop();
+        assert!(!nav.can_go_back());
+        assert!(nav.can_go_forward());
+    }
+}

crates/lore-tui/src/state/command_palette.rs

@@ -0,0 +1,11 @@
+#![allow(dead_code)]
+
+//! Command palette state.
+
+/// State for the command palette overlay.
+#[derive(Debug, Default)]
+pub struct CommandPaletteState {
+    pub query: String,
+    pub query_focused: bool,
+    pub selected_index: usize,
+}

crates/lore-tui/src/state/dashboard.rs

@@ -0,0 +1,10 @@
+#![allow(dead_code)]
+
+//! Dashboard screen state.
+
+/// State for the dashboard summary screen.
+#[derive(Debug, Default)]
+pub struct DashboardState {
+    pub issue_count: u64,
+    pub mr_count: u64,
+}

crates/lore-tui/src/state/issue_detail.rs

@@ -0,0 +1,14 @@
+#![allow(dead_code)]
+
+//! Issue detail screen state.
+
+use crate::message::{Discussion, EntityKey, IssueDetail};
+
+/// State for the issue detail screen.
+#[derive(Debug, Default)]
+pub struct IssueDetailState {
+    pub key: Option<EntityKey>,
+    pub detail: Option<IssueDetail>,
+    pub discussions: Vec<Discussion>,
+    pub scroll_offset: u16,
+}

crates/lore-tui/src/state/issue_list.rs

@@ -0,0 +1,14 @@
+#![allow(dead_code)]
+
+//! Issue list screen state.
+
+use crate::message::IssueRow;
+
+/// State for the issue list screen.
+#[derive(Debug, Default)]
+pub struct IssueListState {
+    pub rows: Vec<IssueRow>,
+    pub filter: String,
+    pub filter_focused: bool,
+    pub selected_index: usize,
+}

crates/lore-tui/src/state/mod.rs

@@ -0,0 +1,335 @@
+#![allow(dead_code)] // Phase 1: consumed by LoreApp in bd-6pmy
+
+//! Top-level state composition for the TUI.
+//!
+//! Each screen has its own state struct. State is preserved when
+//! navigating away — screens are never cleared on pop.
+//!
+//! [`LoadState`] enables stale-while-revalidate: screens show the last
+//! available data during a refresh, with a spinner indicating the load.
+//!
+//! [`ScreenIntent`] is the pure return type from state handlers — they
+//! never spawn async tasks directly. The intent is interpreted by
+//! [`LoreApp`](crate::app::LoreApp) which dispatches through the
+//! [`TaskSupervisor`](crate::task_supervisor::TaskSupervisor).
+
+pub mod command_palette;
+pub mod dashboard;
+pub mod issue_detail;
+pub mod issue_list;
+pub mod mr_detail;
+pub mod mr_list;
+pub mod search;
+pub mod sync;
+pub mod timeline;
+pub mod who;
+
+use std::collections::HashMap;
+
+use crate::message::Screen;
+
+// Re-export screen states for convenience.
+pub use command_palette::CommandPaletteState;
+pub use dashboard::DashboardState;
+pub use issue_detail::IssueDetailState;
+pub use issue_list::IssueListState;
+pub use mr_detail::MrDetailState;
+pub use mr_list::MrListState;
+pub use search::SearchState;
+pub use sync::SyncState;
+pub use timeline::TimelineState;
+pub use who::WhoState;
+
+// ---------------------------------------------------------------------------
+// LoadState
+// ---------------------------------------------------------------------------
+
+/// Loading state for a screen's data.
+///
+/// Enables stale-while-revalidate: screens render their last data while
+/// showing a spinner when `Refreshing`.
+#[derive(Debug, Clone, PartialEq, Eq, Default)]
+pub enum LoadState {
+    /// No load in progress, data is current (or screen was never loaded).
+    #[default]
+    Idle,
+    /// First load — no data to show yet, display a full-screen spinner.
+    LoadingInitial,
+    /// Background refresh — show existing data with a spinner indicator.
+    Refreshing,
+    /// Load failed — display the error alongside any stale data.
+    Error(String),
+}
+
+impl LoadState {
+    /// Whether data is currently being loaded.
+    #[must_use]
+    pub fn is_loading(&self) -> bool {
+        matches!(self, Self::LoadingInitial | Self::Refreshing)
+    }
+}
+
+// ---------------------------------------------------------------------------
+// ScreenLoadStateMap
+// ---------------------------------------------------------------------------
+
+/// Tracks per-screen load state.
+///
+/// Returns [`LoadState::Idle`] for screens that haven't been tracked.
+/// Automatically removes entries set to `Idle` to prevent unbounded growth.
+#[derive(Debug, Default)]
+pub struct ScreenLoadStateMap {
+    map: HashMap<Screen, LoadState>,
+}
+
+impl ScreenLoadStateMap {
+    /// Get the load state for a screen (defaults to `Idle`).
+    #[must_use]
+    pub fn get(&self, screen: &Screen) -> &LoadState {
+        static IDLE: LoadState = LoadState::Idle;
+        self.map.get(screen).unwrap_or(&IDLE)
+    }
+
+    /// Set the load state for a screen.
+    ///
+    /// Setting to `Idle` removes the entry to prevent map growth.
+    pub fn set(&mut self, screen: Screen, state: LoadState) {
+        if state == LoadState::Idle {
+            self.map.remove(&screen);
+        } else {
+            self.map.insert(screen, state);
+        }
+    }
+
+    /// Whether any screen is currently loading.
+    #[must_use]
+    pub fn any_loading(&self) -> bool {
+        self.map.values().any(LoadState::is_loading)
+    }
+}
+
+// ---------------------------------------------------------------------------
+// ScreenIntent
+// ---------------------------------------------------------------------------
+
+/// Pure return type from screen state handlers.
+///
+/// State handlers must never spawn async work directly — they return
+/// an intent that [`LoreApp`] interprets and dispatches through the
+/// [`TaskSupervisor`].
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ScreenIntent {
+    /// No action needed.
+    None,
+    /// Navigate to a new screen.
+    Navigate(Screen),
+    /// Screen data needs re-querying (e.g., filter changed).
+    RequeryNeeded(Screen),
+}
+
+// ---------------------------------------------------------------------------
+// ScopeContext
+// ---------------------------------------------------------------------------
+
+/// Global scope filters applied across all screens.
+///
+/// When a project filter is active, all data queries scope to that
+/// project. The TUI shows the active scope in the status bar.
+#[derive(Debug, Default)]
+pub struct ScopeContext {
+    /// Active project filter (project_id).
+    pub project_id: Option<i64>,
+    /// Human-readable project name for display.
+    pub project_name: Option<String>,
+}
+
+// ---------------------------------------------------------------------------
+// AppState
+// ---------------------------------------------------------------------------
+
+/// Top-level state composition for the TUI.
+///
+/// Each field holds one screen's state. State is preserved when
+/// navigating away and restored on return.
+#[derive(Debug, Default)]
+pub struct AppState {
+    // Per-screen states.
+    pub dashboard: DashboardState,
+    pub issue_list: IssueListState,
+    pub issue_detail: IssueDetailState,
+    pub mr_list: MrListState,
+    pub mr_detail: MrDetailState,
+    pub search: SearchState,
+    pub timeline: TimelineState,
+    pub who: WhoState,
+    pub sync: SyncState,
+    pub command_palette: CommandPaletteState,
+
+    // Cross-cutting state.
+    pub global_scope: ScopeContext,
+    pub load_state: ScreenLoadStateMap,
+    pub error_toast: Option<String>,
+    pub show_help: bool,
+    pub terminal_size: (u16, u16),
+}
+
+impl AppState {
+    /// Set a screen's load state.
+    pub fn set_loading(&mut self, screen: Screen, state: LoadState) {
+        self.load_state.set(screen, state);
+    }
+
+    /// Set the global error toast.
+    pub fn set_error(&mut self, msg: String) {
+        self.error_toast = Some(msg);
+    }
+
+    /// Clear the global error toast.
+    pub fn clear_error(&mut self) {
+        self.error_toast = None;
+    }
+
+    /// Whether any text input is currently focused.
+    #[must_use]
+    pub fn has_text_focus(&self) -> bool {
+        self.issue_list.filter_focused
+            || self.mr_list.filter_focused
+            || self.search.query_focused
+            || self.command_palette.query_focused
+    }
+
+    /// Remove focus from all text inputs.
+    pub fn blur_text_focus(&mut self) {
+        self.issue_list.filter_focused = false;
+        self.mr_list.filter_focused = false;
+        self.search.query_focused = false;
+        self.command_palette.query_focused = false;
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_load_state_default_idle() {
+        let map = ScreenLoadStateMap::default();
+        assert_eq!(*map.get(&Screen::Dashboard), LoadState::Idle);
+        assert_eq!(*map.get(&Screen::IssueList), LoadState::Idle);
+    }
+
+    #[test]
+    fn test_load_state_set_and_get() {
+        let mut map = ScreenLoadStateMap::default();
+        map.set(Screen::Dashboard, LoadState::LoadingInitial);
+        assert_eq!(*map.get(&Screen::Dashboard), LoadState::LoadingInitial);
+        assert_eq!(*map.get(&Screen::IssueList), LoadState::Idle);
+    }
+
+    #[test]
+    fn test_load_state_set_idle_removes_entry() {
+        let mut map = ScreenLoadStateMap::default();
+        map.set(Screen::Dashboard, LoadState::Refreshing);
+        assert_eq!(map.map.len(), 1);
+
+        map.set(Screen::Dashboard, LoadState::Idle);
+        assert_eq!(map.map.len(), 0);
+        assert_eq!(*map.get(&Screen::Dashboard), LoadState::Idle);
+    }
+
+    #[test]
+    fn test_any_loading() {
+        let mut map = ScreenLoadStateMap::default();
+        assert!(!map.any_loading());
+
+        map.set(Screen::Dashboard, LoadState::LoadingInitial);
+        assert!(map.any_loading());
+
+        map.set(Screen::Dashboard, LoadState::Error("oops".into()));
+        assert!(!map.any_loading());
+    }
+
+    #[test]
+    fn test_load_state_is_loading() {
+        assert!(!LoadState::Idle.is_loading());
+        assert!(LoadState::LoadingInitial.is_loading());
+        assert!(LoadState::Refreshing.is_loading());
+        assert!(!LoadState::Error("x".into()).is_loading());
+    }
+
+    #[test]
+    fn test_app_state_default_compiles() {
+        let state = AppState::default();
+        assert!(!state.show_help);
+        assert!(state.error_toast.is_none());
+        assert_eq!(state.terminal_size, (0, 0));
+    }
+
+    #[test]
+    fn test_app_state_set_error_and_clear() {
+        let mut state = AppState::default();
+        state.set_error("db busy".into());
+        assert_eq!(state.error_toast.as_deref(), Some("db busy"));
+
+        state.clear_error();
+        assert!(state.error_toast.is_none());
+    }
+
+    #[test]
+    fn test_app_state_has_text_focus() {
+        let mut state = AppState::default();
+        assert!(!state.has_text_focus());
+
+        state.search.query_focused = true;
+        assert!(state.has_text_focus());
+    }
+
+    #[test]
+    fn test_app_state_blur_text_focus() {
+        let mut state = AppState::default();
+        state.issue_list.filter_focused = true;
+        state.mr_list.filter_focused = true;
+        state.search.query_focused = true;
+        state.command_palette.query_focused = true;
+
+        state.blur_text_focus();
+
+        assert!(!state.has_text_focus());
+        assert!(!state.issue_list.filter_focused);
+        assert!(!state.mr_list.filter_focused);
+        assert!(!state.search.query_focused);
+        assert!(!state.command_palette.query_focused);
+    }
+
+    #[test]
+    fn test_app_state_set_loading() {
+        let mut state = AppState::default();
+        state.set_loading(Screen::IssueList, LoadState::Refreshing);
+        assert_eq!(
+            *state.load_state.get(&Screen::IssueList),
+            LoadState::Refreshing
+        );
+    }
+
+    #[test]
+    fn test_screen_intent_variants() {
+        let none = ScreenIntent::None;
+        let nav = ScreenIntent::Navigate(Screen::IssueList);
+        let requery = ScreenIntent::RequeryNeeded(Screen::Search);
+
+        assert_eq!(none, ScreenIntent::None);
+        assert_eq!(nav, ScreenIntent::Navigate(Screen::IssueList));
+        assert_eq!(requery, ScreenIntent::RequeryNeeded(Screen::Search));
+    }
+
+    #[test]
+    fn test_scope_context_default() {
+        let scope = ScopeContext::default();
+        assert!(scope.project_id.is_none());
+        assert!(scope.project_name.is_none());
+    }
+}

crates/lore-tui/src/state/mr_detail.rs

@@ -0,0 +1,14 @@
+#![allow(dead_code)]
+
+//! Merge request detail screen state.
+
+use crate::message::{Discussion, EntityKey, MrDetail};
+
+/// State for the MR detail screen.
+#[derive(Debug, Default)]
+pub struct MrDetailState {
+    pub key: Option<EntityKey>,
+    pub detail: Option<MrDetail>,
+    pub discussions: Vec<Discussion>,
+    pub scroll_offset: u16,
+}

crates/lore-tui/src/state/mr_list.rs

@@ -0,0 +1,14 @@
+#![allow(dead_code)]
+
+//! Merge request list screen state.
+
+use crate::message::MrRow;
+
+/// State for the MR list screen.
+#[derive(Debug, Default)]
+pub struct MrListState {
+    pub rows: Vec<MrRow>,
+    pub filter: String,
+    pub filter_focused: bool,
+    pub selected_index: usize,
+}

crates/lore-tui/src/state/search.rs

@@ -0,0 +1,14 @@
+#![allow(dead_code)]
+
+//! Search screen state.
+
+use crate::message::SearchResult;
+
+/// State for the search screen.
+#[derive(Debug, Default)]
+pub struct SearchState {
+    pub query: String,
+    pub query_focused: bool,
+    pub results: Vec<SearchResult>,
+    pub selected_index: usize,
+}

crates/lore-tui/src/state/sync.rs

@@ -0,0 +1,15 @@
+#![allow(dead_code)]
+
+//! Sync screen state.
+
+/// State for the sync progress/summary screen.
+#[derive(Debug, Default)]
+pub struct SyncState {
+    pub stage: String,
+    pub current: u64,
+    pub total: u64,
+    pub log_lines: Vec<String>,
+    pub completed: bool,
+    pub elapsed_ms: Option<u64>,
+    pub error: Option<String>,
+}

crates/lore-tui/src/state/timeline.rs

@@ -0,0 +1,12 @@
+#![allow(dead_code)]
+
+//! Timeline screen state.
+
+use crate::message::TimelineEvent;
+
+/// State for the timeline screen.
+#[derive(Debug, Default)]
+pub struct TimelineState {
+    pub events: Vec<TimelineEvent>,
+    pub scroll_offset: u16,
+}

crates/lore-tui/src/state/who.rs

@@ -0,0 +1,12 @@
+#![allow(dead_code)]
+
+//! Who (people intelligence) screen state.
+
+use crate::message::WhoResult;
+
+/// State for the who/people screen.
+#[derive(Debug, Default)]
+pub struct WhoState {
+    pub result: Option<WhoResult>,
+    pub scroll_offset: u16,
+}

crates/lore-tui/src/task_supervisor.rs

@@ -0,0 +1,380 @@
+#![allow(dead_code)] // Phase 1: consumed by LoreApp in bd-6pmy
+
+//! Centralized background task management with dedup and cancellation.
+//!
+//! All background work (DB queries, sync, search) flows through
+//! [`TaskSupervisor`]. Submitting a task with a key that already has an
+//! active handle cancels the previous task via its [`CancelToken`] and
+//! bumps the generation counter.
+//!
+//! Generation IDs enable stale-result detection: when an async result
+//! arrives, [`is_current`] checks whether the result's generation
+//! matches the latest submission for that key.
+
+use std::collections::HashMap;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
+
+use crate::message::Screen;
+
+// ---------------------------------------------------------------------------
+// TaskKey
+// ---------------------------------------------------------------------------
+
+/// Deduplication key for background tasks.
+///
+/// Two tasks with the same key cannot run concurrently — submitting a
+/// new task with an existing key cancels the previous one.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum TaskKey {
+    /// Load data for a specific screen.
+    LoadScreen(Screen),
+    /// Global search query.
+    Search,
+    /// Sync stream (only one at a time).
+    SyncStream,
+    /// Re-query after filter change on a specific screen.
+    FilterRequery(Screen),
+}
+
+// ---------------------------------------------------------------------------
+// TaskPriority
+// ---------------------------------------------------------------------------
+
+/// Priority levels for task scheduling.
+///
+/// Lower numeric value = higher priority.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub enum TaskPriority {
+    /// User-initiated input (highest priority).
+    Input = 0,
+    /// Navigation-triggered data load.
+    Navigation = 1,
+    /// Background refresh / prefetch (lowest priority).
+    Background = 2,
+}
+
+// ---------------------------------------------------------------------------
+// CancelToken
+// ---------------------------------------------------------------------------
+
+/// Thread-safe cooperative cancellation flag.
+///
+/// Background tasks poll [`is_cancelled`] periodically and exit early
+/// when it returns `true`.
+#[derive(Debug)]
+pub struct CancelToken {
+    cancelled: AtomicBool,
+}
+
+impl CancelToken {
+    /// Create a new, non-cancelled token.
+    #[must_use]
+    pub fn new() -> Self {
+        Self {
+            cancelled: AtomicBool::new(false),
+        }
+    }
+
+    /// Signal cancellation.
+    pub fn cancel(&self) {
+        self.cancelled.store(true, Ordering::Relaxed);
+    }
+
+    /// Check whether cancellation has been requested.
+    #[must_use]
+    pub fn is_cancelled(&self) -> bool {
+        self.cancelled.load(Ordering::Relaxed)
+    }
+}
+
+impl Default for CancelToken {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+// ---------------------------------------------------------------------------
+// InterruptHandle
+// ---------------------------------------------------------------------------
+
+/// Opaque handle for interrupting a rusqlite operation.
+///
+/// Wraps the rusqlite `InterruptHandle` so the supervisor can cancel
+/// long-running queries. This is only set for tasks that lease a reader
+/// connection from [`DbManager`](crate::db::DbManager).
+pub struct InterruptHandle {
+    handle: rusqlite::InterruptHandle,
+}
+
+impl std::fmt::Debug for InterruptHandle {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("InterruptHandle").finish_non_exhaustive()
+    }
+}
+
+impl InterruptHandle {
+    /// Wrap a rusqlite interrupt handle.
+    #[must_use]
+    pub fn new(handle: rusqlite::InterruptHandle) -> Self {
+        Self { handle }
+    }
+
+    /// Interrupt the associated SQLite operation.
+    pub fn interrupt(&self) {
+        self.handle.interrupt();
+    }
+}
+
+// ---------------------------------------------------------------------------
+// TaskHandle
+// ---------------------------------------------------------------------------
+
+/// Handle returned when a task is submitted.
+///
+/// Callers use this to pass the generation ID into async work so
+/// results can be tagged and checked for staleness.
+#[derive(Debug)]
+pub struct TaskHandle {
+    /// Dedup key for this task.
+    pub key: TaskKey,
+    /// Monotonically increasing generation for stale detection.
+    pub generation: u64,
+    /// Cooperative cancellation token (shared with the supervisor).
+    pub cancel: Arc<CancelToken>,
+    /// Optional SQLite interrupt handle for long queries.
+    pub interrupt: Option<InterruptHandle>,
+}
+
+// ---------------------------------------------------------------------------
+// TaskSupervisor
+// ---------------------------------------------------------------------------
+
+/// Manages background tasks with deduplication and cancellation.
+///
+/// Only one task per [`TaskKey`] can be active. Submitting a new task
+/// with an existing key cancels the previous one (via its cancel token
+/// and optional interrupt handle) before registering the new handle.
+pub struct TaskSupervisor {
+    active: HashMap<TaskKey, TaskHandle>,
+    next_generation: AtomicU64,
+}
+
+impl TaskSupervisor {
+    /// Create a new supervisor with no active tasks.
+    #[must_use]
+    pub fn new() -> Self {
+        Self {
+            active: HashMap::new(),
+            next_generation: AtomicU64::new(1),
+        }
+    }
+
+    /// Submit a new task, cancelling any existing task with the same key.
+    ///
+    /// Returns a [`TaskHandle`] with a fresh generation ID and a shared
+    /// cancel token. The caller clones the `Arc<CancelToken>` and passes
+    /// it into the async work.
+    pub fn submit(&mut self, key: TaskKey) -> &TaskHandle {
+        // Cancel existing task with this key, if any.
+        if let Some(old) = self.active.remove(&key) {
+            old.cancel.cancel();
+            if let Some(interrupt) = &old.interrupt {
+                interrupt.interrupt();
+            }
+        }
+
+        let generation = self.next_generation.fetch_add(1, Ordering::Relaxed);
+        let cancel = Arc::new(CancelToken::new());
+
+        let handle = TaskHandle {
+            key: key.clone(),
+            generation,
+            cancel,
+            interrupt: None,
+        };
+
+        self.active.insert(key.clone(), handle);
+        self.active.get(&key).expect("just inserted")
+    }
+
+    /// Check whether a generation is current for a given key.
+    ///
+    /// Returns `true` only if the key has an active handle with the
+    /// specified generation.
+    #[must_use]
+    pub fn is_current(&self, key: &TaskKey, generation: u64) -> bool {
+        self.active
+            .get(key)
+            .is_some_and(|h| h.generation == generation)
+    }
+
+    /// Mark a task as complete, removing its handle.
+    ///
+    /// Only removes the handle if the generation matches the active one.
+    /// This prevents a late-arriving completion from removing a newer
+    /// task's handle.
+    pub fn complete(&mut self, key: &TaskKey, generation: u64) {
+        if self.is_current(key, generation) {
+            self.active.remove(key);
+        }
+    }
+
+    /// Cancel all active tasks.
+    ///
+    /// Used during shutdown to ensure background work stops promptly.
+    pub fn cancel_all(&mut self) {
+        for (_, handle) in self.active.drain() {
+            handle.cancel.cancel();
+            if let Some(interrupt) = &handle.interrupt {
+                interrupt.interrupt();
+            }
+        }
+    }
+
+    /// Number of currently active tasks.
+    #[must_use]
+    pub fn active_count(&self) -> usize {
+        self.active.len()
+    }
+}
+
+impl Default for TaskSupervisor {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_submit_cancels_previous() {
+        let mut sup = TaskSupervisor::new();
+
+        let gen1 = sup.submit(TaskKey::Search).generation;
+        let cancel1 = sup.active.get(&TaskKey::Search).unwrap().cancel.clone();
+
+        let gen2 = sup.submit(TaskKey::Search).generation;
+
+        // First task's token should be cancelled.
+        assert!(cancel1.is_cancelled());
+        // Second task should have a different (higher) generation.
+        assert!(gen2 > gen1);
+        // Only one active task for this key.
+        assert_eq!(sup.active_count(), 1);
+    }
+
+    #[test]
+    fn test_is_current_after_supersede() {
+        let mut sup = TaskSupervisor::new();
+
+        let gen1 = sup.submit(TaskKey::Search).generation;
+        let gen2 = sup.submit(TaskKey::Search).generation;
+
+        assert!(!sup.is_current(&TaskKey::Search, gen1));
+        assert!(sup.is_current(&TaskKey::Search, gen2));
+    }
+
+    #[test]
+    fn test_complete_removes_handle() {
+        let mut sup = TaskSupervisor::new();
+        let generation = sup.submit(TaskKey::Search).generation;
+
+        assert_eq!(sup.active_count(), 1);
+        sup.complete(&TaskKey::Search, generation);
+        assert_eq!(sup.active_count(), 0);
+    }
+
+    #[test]
+    fn test_complete_ignores_stale() {
+        let mut sup = TaskSupervisor::new();
+
+        let gen1 = sup.submit(TaskKey::Search).generation;
+        let gen2 = sup.submit(TaskKey::Search).generation;
+
+        // Completing with old generation should NOT remove the newer handle.
+        sup.complete(&TaskKey::Search, gen1);
+        assert_eq!(sup.active_count(), 1);
+        assert!(sup.is_current(&TaskKey::Search, gen2));
+    }
+
+    #[test]
+    fn test_generation_monotonic() {
+        let mut sup = TaskSupervisor::new();
+
+        let g1 = sup.submit(TaskKey::Search).generation;
+        let g2 = sup.submit(TaskKey::SyncStream).generation;
+        let g3 = sup.submit(TaskKey::Search).generation;
+
+        assert!(g1 < g2);
+        assert!(g2 < g3);
+    }
+
+    #[test]
+    fn test_different_keys_coexist() {
+        let mut sup = TaskSupervisor::new();
+
+        sup.submit(TaskKey::Search);
+        sup.submit(TaskKey::SyncStream);
+        sup.submit(TaskKey::LoadScreen(Screen::Dashboard));
+
+        assert_eq!(sup.active_count(), 3);
+    }
+
+    #[test]
+    fn test_cancel_all() {
+        let mut sup = TaskSupervisor::new();
+
+        let cancel_search = {
+            sup.submit(TaskKey::Search);
+            sup.active.get(&TaskKey::Search).unwrap().cancel.clone()
+        };
+        let cancel_sync = {
+            sup.submit(TaskKey::SyncStream);
+            sup.active.get(&TaskKey::SyncStream).unwrap().cancel.clone()
+        };
+
+        sup.cancel_all();
+
+        assert!(cancel_search.is_cancelled());
+        assert!(cancel_sync.is_cancelled());
+        assert_eq!(sup.active_count(), 0);
+    }
+
+    #[test]
+    fn test_cancel_token_default_is_not_cancelled() {
+        let token = CancelToken::new();
+        assert!(!token.is_cancelled());
+        token.cancel();
+        assert!(token.is_cancelled());
+    }
+
+    #[test]
+    fn test_cancel_token_is_send_sync() {
+        fn assert_send_sync<T: Send + Sync>() {}
+        assert_send_sync::<CancelToken>();
+        assert_send_sync::<Arc<CancelToken>>();
+    }
+
+    #[test]
+    fn test_task_supervisor_default() {
+        let sup = TaskSupervisor::default();
+        assert_eq!(sup.active_count(), 0);
+    }
+
+    #[test]
+    fn test_filter_requery_key_distinct_per_screen() {
+        let mut sup = TaskSupervisor::new();
+
+        sup.submit(TaskKey::FilterRequery(Screen::IssueList));
+        sup.submit(TaskKey::FilterRequery(Screen::MrList));
+
+        assert_eq!(sup.active_count(), 2);
+    }
+}

crates/lore-tui/src/view/common/mod.rs

@@ -0,0 +1,816 @@
+#![allow(dead_code)] // Phase 1: consumed by screen views in Phase 2+
+
+//! Common widgets shared across all TUI screens.
+//!
+//! These are pure rendering functions — they write directly into the
+//! [`Frame`] buffer using ftui's `Draw` trait. No state mutation,
+//! no side effects.
+//!
+//! - [`render_breadcrumb`] — navigation trail ("Dashboard > Issues > #42")
+//! - [`render_status_bar`] — bottom bar with key hints and mode indicator
+//! - [`render_loading`] — full-screen spinner or subtle refresh indicator
+//! - [`render_error_toast`] — floating error message at bottom-right
+//! - [`render_help_overlay`] — centered modal listing keybindings
+
+use ftui::core::geometry::Rect;
+use ftui::render::cell::{Cell, PackedRgba};
+use ftui::render::drawing::Draw;
+use ftui::render::frame::Frame;
+
+use crate::commands::CommandRegistry;
+use crate::message::{InputMode, Screen};
+use crate::navigation::NavigationStack;
+use crate::state::LoadState;
+
+// ---------------------------------------------------------------------------
+// Spinner frames
+// ---------------------------------------------------------------------------
+
+/// Braille spinner frames for loading animation.
+const SPINNER_FRAMES: &[char] = &['⠋', '⠙', '⠹', '⠸', '⠼', '⠴', '⠦', '⠧', '⠇', '⠏'];
+
+/// Select spinner frame from tick count.
+#[must_use]
+fn spinner_char(tick: u64) -> char {
+    SPINNER_FRAMES[(tick as usize) % SPINNER_FRAMES.len()]
+}
+
+// ---------------------------------------------------------------------------
+// render_breadcrumb
+// ---------------------------------------------------------------------------
+
+/// Render the navigation breadcrumb trail.
+///
+/// Shows "Dashboard > Issues > Issue" with " > " separators. When the
+/// trail exceeds the available width, entries are truncated from the left
+/// with a leading "...".
+pub fn render_breadcrumb(
+    frame: &mut Frame<'_>,
+    area: Rect,
+    nav: &NavigationStack,
+    text_color: PackedRgba,
+    muted_color: PackedRgba,
+) {
+    if area.height == 0 || area.width < 3 {
+        return;
+    }
+
+    let crumbs = nav.breadcrumbs();
+    let separator = " > ";
+
+    // Build the full breadcrumb string and calculate width.
+    let full: String = crumbs.join(separator);
+    let max_width = area.width as usize;
+
+    let display = if full.len() <= max_width {
+        full
+    } else {
+        // Truncate from the left: show "... > last_crumbs"
+        truncate_breadcrumb_left(&crumbs, separator, max_width)
+    };
+
+    let base = Cell {
+        fg: text_color,
+        ..Cell::default()
+    };
+    let muted = Cell {
+        fg: muted_color,
+        ..Cell::default()
+    };
+
+    // Render each segment with separators in muted color.
+    let mut x = area.x;
+    let max_x = area.x.saturating_add(area.width);
+
+    if let Some(rest) = display.strip_prefix("...") {
+        // Render ellipsis in muted, then the rest
+        x = frame.print_text_clipped(x, area.y, "...", muted, max_x);
+        if !rest.is_empty() {
+            render_crumb_segments(frame, x, area.y, rest, separator, base, muted, max_x);
+        }
+    } else {
+        render_crumb_segments(frame, x, area.y, &display, separator, base, muted, max_x);
+    }
+}
+
+/// Render breadcrumb text with separators in muted color.
+#[allow(clippy::too_many_arguments)]
+fn render_crumb_segments(
+    frame: &mut Frame<'_>,
+    start_x: u16,
+    y: u16,
+    text: &str,
+    separator: &str,
+    base: Cell,
+    muted: Cell,
+    max_x: u16,
+) {
+    let mut x = start_x;
+    let parts: Vec<&str> = text.split(separator).collect();
+
+    for (i, part) in parts.iter().enumerate() {
+        if i > 0 {
+            x = frame.print_text_clipped(x, y, separator, muted, max_x);
+        }
+        x = frame.print_text_clipped(x, y, part, base, max_x);
+        if x >= max_x {
+            break;
+        }
+    }
+}
+
+/// Truncate breadcrumb from the left to fit within max_width.
+fn truncate_breadcrumb_left(crumbs: &[&str], separator: &str, max_width: usize) -> String {
+    let ellipsis = "...";
+
+    // Try showing progressively fewer crumbs from the right.
+    for skip in 1..crumbs.len() {
+        let tail = &crumbs[skip..];
+        let tail_str: String = tail.join(separator);
+        let candidate = format!("{ellipsis}{separator}{tail_str}");
+        if candidate.len() <= max_width {
+            return candidate;
+        }
+    }
+
+    // Last resort: just the current screen truncated.
+    let last = crumbs.last().unwrap_or(&"");
+    if last.len() + ellipsis.len() <= max_width {
+        return format!("{ellipsis}{last}");
+    }
+
+    // Truly tiny terminal: just ellipsis.
+    ellipsis.to_string()
+}
+
+// ---------------------------------------------------------------------------
+// render_status_bar
+// ---------------------------------------------------------------------------
+
+/// Render the bottom status bar with key hints and mode indicator.
+///
+/// Layout: `[mode] ─── [key hints]`
+///
+/// Key hints are sourced from the [`CommandRegistry`] filtered to the
+/// current screen, showing only the most important bindings.
+#[allow(clippy::too_many_arguments)]
+pub fn render_status_bar(
+    frame: &mut Frame<'_>,
+    area: Rect,
+    registry: &CommandRegistry,
+    screen: &Screen,
+    mode: &InputMode,
+    bar_bg: PackedRgba,
+    text_color: PackedRgba,
+    accent_color: PackedRgba,
+) {
+    if area.height == 0 || area.width < 5 {
+        return;
+    }
+
+    // Fill the bar background.
+    let bg_cell = Cell {
+        bg: bar_bg,
+        ..Cell::default()
+    };
+    frame.draw_rect_filled(area, bg_cell);
+
+    let mode_label = match mode {
+        InputMode::Normal => "NORMAL",
+        InputMode::Text => "INPUT",
+        InputMode::Palette => "PALETTE",
+        InputMode::GoPrefix { .. } => "g...",
+    };
+
+    // Left side: mode indicator.
+    let mode_cell = Cell {
+        fg: accent_color,
+        bg: bar_bg,
+        ..Cell::default()
+    };
+    let mut x = frame.print_text_clipped(
+        area.x.saturating_add(1),
+        area.y,
+        mode_label,
+        mode_cell,
+        area.right(),
+    );
+
+    // Spacer.
+    x = x.saturating_add(2);
+
+    // Right side: key hints from registry (formatted as "key:action").
+    let hints = registry.status_hints(screen);
+    let hint_cell = Cell {
+        fg: text_color,
+        bg: bar_bg,
+        ..Cell::default()
+    };
+    let key_cell = Cell {
+        fg: accent_color,
+        bg: bar_bg,
+        ..Cell::default()
+    };
+
+    for hint in &hints {
+        if x >= area.right().saturating_sub(1) {
+            break;
+        }
+        // Split "q:quit" into key part and description part.
+        if let Some((key_part, desc_part)) = hint.split_once(':') {
+            x = frame.print_text_clipped(x, area.y, key_part, key_cell, area.right());
+            x = frame.print_text_clipped(x, area.y, ":", hint_cell, area.right());
+            x = frame.print_text_clipped(x, area.y, desc_part, hint_cell, area.right());
+        } else {
+            x = frame.print_text_clipped(x, area.y, hint, hint_cell, area.right());
+        }
+        x = x.saturating_add(2);
+    }
+}
+
+// ---------------------------------------------------------------------------
+// render_loading
+// ---------------------------------------------------------------------------
+
+/// Render a loading indicator.
+///
+/// - `LoadingInitial`: centered full-screen spinner with "Loading..."
+/// - `Refreshing`: subtle spinner in top-right corner
+/// - Other states: no-op
+pub fn render_loading(
+    frame: &mut Frame<'_>,
+    area: Rect,
+    load_state: &LoadState,
+    text_color: PackedRgba,
+    muted_color: PackedRgba,
+    tick: u64,
+) {
+    match load_state {
+        LoadState::LoadingInitial => {
+            render_centered_spinner(frame, area, "Loading...", text_color, tick);
+        }
+        LoadState::Refreshing => {
+            render_corner_spinner(frame, area, muted_color, tick);
+        }
+        _ => {}
+    }
+}
+
+/// Render a centered spinner with message.
+fn render_centered_spinner(
+    frame: &mut Frame<'_>,
+    area: Rect,
+    message: &str,
+    color: PackedRgba,
+    tick: u64,
+) {
+    if area.height == 0 || area.width < 5 {
+        return;
+    }
+
+    let spinner = spinner_char(tick);
+    let text = format!("{spinner} {message}");
+    let text_len = text.len() as u16;
+
+    // Center horizontally and vertically.
+    let x = area
+        .x
+        .saturating_add(area.width.saturating_sub(text_len) / 2);
+    let y = area.y.saturating_add(area.height / 2);
+
+    let cell = Cell {
+        fg: color,
+        ..Cell::default()
+    };
+    frame.print_text_clipped(x, y, &text, cell, area.right());
+}
+
+/// Render a subtle spinner in the top-right corner.
+fn render_corner_spinner(frame: &mut Frame<'_>, area: Rect, color: PackedRgba, tick: u64) {
+    if area.width < 2 || area.height == 0 {
+        return;
+    }
+
+    let spinner = spinner_char(tick);
+    let x = area.right().saturating_sub(2);
+    let y = area.y;
+
+    let cell = Cell {
+        fg: color,
+        ..Cell::default()
+    };
+    frame.print_text_clipped(x, y, &spinner.to_string(), cell, area.right());
+}
+
+// ---------------------------------------------------------------------------
+// render_error_toast
+// ---------------------------------------------------------------------------
+
+/// Render a floating error toast at the bottom-right of the area.
+///
+/// The toast has a colored background and truncates long messages.
+pub fn render_error_toast(
+    frame: &mut Frame<'_>,
+    area: Rect,
+    msg: &str,
+    error_bg: PackedRgba,
+    error_fg: PackedRgba,
+) {
+    if area.height < 3 || area.width < 10 || msg.is_empty() {
+        return;
+    }
+
+    // Toast dimensions: message + padding, max 60 chars or half screen.
+    let max_toast_width = (area.width / 2).clamp(20, 60);
+    let toast_text = if msg.len() as u16 > max_toast_width.saturating_sub(4) {
+        let trunc_len = max_toast_width.saturating_sub(7) as usize;
+        format!(" {}... ", &msg[..trunc_len.min(msg.len())])
+    } else {
+        format!(" {msg} ")
+    };
+    let toast_width = toast_text.len() as u16;
+    let toast_height: u16 = 1;
+
+    // Position: bottom-right with 1-cell margin.
+    let x = area.right().saturating_sub(toast_width + 1);
+    let y = area.bottom().saturating_sub(toast_height + 1);
+
+    let toast_rect = Rect::new(x, y, toast_width, toast_height);
+
+    // Fill background.
+    let bg_cell = Cell {
+        bg: error_bg,
+        ..Cell::default()
+    };
+    frame.draw_rect_filled(toast_rect, bg_cell);
+
+    // Render text.
+    let text_cell = Cell {
+        fg: error_fg,
+        bg: error_bg,
+        ..Cell::default()
+    };
+    frame.print_text_clipped(x, y, &toast_text, text_cell, area.right());
+}
+
+// ---------------------------------------------------------------------------
+// render_help_overlay
+// ---------------------------------------------------------------------------
+
+/// Render a centered help overlay listing keybindings for the current screen.
+///
+/// The overlay is a bordered modal that lists all commands from the
+/// registry that are available on the current screen.
+#[allow(clippy::too_many_arguments)]
+pub fn render_help_overlay(
+    frame: &mut Frame<'_>,
+    area: Rect,
+    registry: &CommandRegistry,
+    screen: &Screen,
+    border_color: PackedRgba,
+    text_color: PackedRgba,
+    muted_color: PackedRgba,
+    scroll_offset: usize,
+) {
+    if area.height < 5 || area.width < 20 {
+        return;
+    }
+
+    // Overlay dimensions: 60% of screen, capped.
+    let overlay_width = (area.width * 3 / 5).clamp(30, 70);
+    let overlay_height = (area.height * 3 / 5).clamp(8, 30);
+
+    let overlay_x = area.x + (area.width.saturating_sub(overlay_width)) / 2;
+    let overlay_y = area.y + (area.height.saturating_sub(overlay_height)) / 2;
+    let overlay_rect = Rect::new(overlay_x, overlay_y, overlay_width, overlay_height);
+
+    // Draw border.
+    let border_cell = Cell {
+        fg: border_color,
+        ..Cell::default()
+    };
+    frame.draw_border(
+        overlay_rect,
+        ftui::render::drawing::BorderChars::ROUNDED,
+        border_cell,
+    );
+
+    // Title.
+    let title = " Help (? to close) ";
+    let title_x = overlay_x + (overlay_width.saturating_sub(title.len() as u16)) / 2;
+    let title_cell = Cell {
+        fg: border_color,
+        ..Cell::default()
+    };
+    frame.print_text_clipped(title_x, overlay_y, title, title_cell, overlay_rect.right());
+
+    // Inner content area (inside border).
+    let inner = Rect::new(
+        overlay_x + 2,
+        overlay_y + 1,
+        overlay_width.saturating_sub(4),
+        overlay_height.saturating_sub(2),
+    );
+
+    // Get commands for this screen.
+    let commands = registry.help_entries(screen);
+    let visible_lines = inner.height as usize;
+
+    let key_cell = Cell {
+        fg: text_color,
+        ..Cell::default()
+    };
+    let desc_cell = Cell {
+        fg: muted_color,
+        ..Cell::default()
+    };
+
+    for (i, cmd) in commands.iter().skip(scroll_offset).enumerate() {
+        if i >= visible_lines {
+            break;
+        }
+        let y = inner.y + i as u16;
+
+        // Key binding label (left).
+        let key_label = cmd
+            .keybinding
+            .as_ref()
+            .map_or_else(String::new, |kb| kb.display());
+        let label_end = frame.print_text_clipped(inner.x, y, &key_label, key_cell, inner.right());
+
+        // Spacer + description (right).
+        let desc_x = label_end.saturating_add(2);
+        if desc_x < inner.right() {
+            frame.print_text_clipped(desc_x, y, cmd.help_text, desc_cell, inner.right());
+        }
+    }
+
+    // Scroll indicator if needed.
+    if commands.len() > visible_lines + scroll_offset {
+        let indicator = format!("({}/{})", scroll_offset + visible_lines, commands.len());
+        let ind_x = inner.right().saturating_sub(indicator.len() as u16);
+        let ind_y = overlay_rect.bottom().saturating_sub(1);
+        frame.print_text_clipped(ind_x, ind_y, &indicator, desc_cell, overlay_rect.right());
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::commands::build_registry;
+    use crate::message::Screen;
+    use crate::navigation::NavigationStack;
+    use crate::state::LoadState;
+    use ftui::render::grapheme_pool::GraphemePool;
+
+    macro_rules! with_frame {
+        ($width:expr, $height:expr, |$frame:ident| $body:block) => {{
+            let mut pool = GraphemePool::new();
+            let mut $frame = Frame::new($width, $height, &mut pool);
+            $body
+        }};
+    }
+
+    fn white() -> PackedRgba {
+        PackedRgba::rgb(0xFF, 0xFF, 0xFF)
+    }
+
+    fn gray() -> PackedRgba {
+        PackedRgba::rgb(0x80, 0x80, 0x80)
+    }
+
+    fn red_bg() -> PackedRgba {
+        PackedRgba::rgb(0xFF, 0x00, 0x00)
+    }
+
+    // --- Breadcrumb tests ---
+
+    #[test]
+    fn test_breadcrumb_single_screen() {
+        with_frame!(80, 1, |frame| {
+            let nav = NavigationStack::new(); // Dashboard only
+            render_breadcrumb(&mut frame, Rect::new(0, 0, 80, 1), &nav, white(), gray());
+
+            // Verify "Dashboard" was rendered by checking first cell.
+            let cell = frame.buffer.get(0, 0).unwrap();
+            assert!(
+                cell.content.as_char() == Some('D'),
+                "Expected 'D' at (0,0), got {:?}",
+                cell.content.as_char()
+            );
+        });
+    }
+
+    #[test]
+    fn test_breadcrumb_multi_screen() {
+        with_frame!(80, 1, |frame| {
+            let mut nav = NavigationStack::new();
+            nav.push(Screen::IssueList);
+            render_breadcrumb(&mut frame, Rect::new(0, 0, 80, 1), &nav, white(), gray());
+
+            // Should render "Dashboard > Issues"
+            // Check 'D' at start and 'I' after separator.
+            let d = frame.buffer.get(0, 0).unwrap();
+            assert_eq!(d.content.as_char(), Some('D'));
+
+            // "Dashboard > Issues" = 'D' at 0, ' > ' at 9, 'I' at 12
+            let i_cell = frame.buffer.get(12, 0).unwrap();
+            assert_eq!(i_cell.content.as_char(), Some('I'));
+        });
+    }
+
+    #[test]
+    fn test_breadcrumb_truncation() {
+        // Very narrow terminal — should show "..." prefix.
+        let crumbs = vec!["Dashboard", "Issues", "Issue"];
+        let result = truncate_breadcrumb_left(&crumbs, " > ", 20);
+        assert!(
+            result.starts_with("..."),
+            "Expected ellipsis prefix, got: {result}"
+        );
+        assert!(result.len() <= 20, "Result too long: {result}");
+    }
+
+    #[test]
+    fn test_breadcrumb_zero_height_noop() {
+        // Frame requires height >= 1, but Rect can have height=0.
+        with_frame!(80, 1, |frame| {
+            let nav = NavigationStack::new();
+            // Should not panic — early return for zero-height area.
+            render_breadcrumb(&mut frame, Rect::new(0, 0, 80, 0), &nav, white(), gray());
+        });
+    }
+
+    // --- Status bar tests ---
+
+    #[test]
+    fn test_status_bar_renders_mode() {
+        with_frame!(80, 1, |frame| {
+            let registry = build_registry();
+            render_status_bar(
+                &mut frame,
+                Rect::new(0, 0, 80, 1),
+                &registry,
+                &Screen::Dashboard,
+                &InputMode::Normal,
+                gray(),
+                white(),
+                white(),
+            );
+
+            // "NORMAL" should appear starting at x=1.
+            let n_cell = frame.buffer.get(1, 0).unwrap();
+            assert_eq!(n_cell.content.as_char(), Some('N'));
+        });
+    }
+
+    #[test]
+    fn test_status_bar_text_mode() {
+        with_frame!(80, 1, |frame| {
+            let registry = build_registry();
+            render_status_bar(
+                &mut frame,
+                Rect::new(0, 0, 80, 1),
+                &registry,
+                &Screen::Search,
+                &InputMode::Text,
+                gray(),
+                white(),
+                white(),
+            );
+
+            // "INPUT" should appear at x=1.
+            let i_cell = frame.buffer.get(1, 0).unwrap();
+            assert_eq!(i_cell.content.as_char(), Some('I'));
+        });
+    }
+
+    #[test]
+    fn test_status_bar_narrow_terminal() {
+        with_frame!(4, 1, |frame| {
+            let registry = build_registry();
+            // Width < 5, should be a no-op.
+            render_status_bar(
+                &mut frame,
+                Rect::new(0, 0, 4, 1),
+                &registry,
+                &Screen::Dashboard,
+                &InputMode::Normal,
+                gray(),
+                white(),
+                white(),
+            );
+            // First cell should be empty (no-op).
+            let cell = frame.buffer.get(0, 0).unwrap();
+            assert!(cell.is_empty());
+        });
+    }
+
+    // --- Loading indicator tests ---
+
+    #[test]
+    fn test_loading_initial_renders_spinner() {
+        with_frame!(80, 24, |frame| {
+            render_loading(
+                &mut frame,
+                Rect::new(0, 0, 80, 24),
+                &LoadState::LoadingInitial,
+                white(),
+                gray(),
+                0,
+            );
+
+            // Spinner should be centered at y=12.
+            // The spinner char is at the center position.
+            let center_y = 12u16;
+            // Find any non-empty cell on the center row.
+            let has_content = (0..80u16).any(|x| {
+                let cell = frame.buffer.get(x, center_y).unwrap();
+                !cell.is_empty()
+            });
+            assert!(has_content, "Expected loading spinner at center row");
+        });
+    }
+
+    #[test]
+    fn test_loading_refreshing_renders_corner() {
+        with_frame!(80, 24, |frame| {
+            render_loading(
+                &mut frame,
+                Rect::new(0, 0, 80, 24),
+                &LoadState::Refreshing,
+                white(),
+                gray(),
+                0,
+            );
+
+            // Corner spinner should be at (78, 0).
+            let cell = frame.buffer.get(78, 0).unwrap();
+            assert!(!cell.is_empty(), "Expected corner spinner");
+        });
+    }
+
+    #[test]
+    fn test_loading_idle_noop() {
+        with_frame!(80, 24, |frame| {
+            render_loading(
+                &mut frame,
+                Rect::new(0, 0, 80, 24),
+                &LoadState::Idle,
+                white(),
+                gray(),
+                0,
+            );
+
+            // All cells should be empty.
+            let has_content = (0..80u16).any(|x| {
+                (0..24u16).any(|y| {
+                    let cell = frame.buffer.get(x, y).unwrap();
+                    !cell.is_empty()
+                })
+            });
+            assert!(!has_content, "Idle state should render nothing");
+        });
+    }
+
+    #[test]
+    fn test_spinner_animation_cycles() {
+        // Different tick values produce different spinner chars.
+        let frame0 = spinner_char(0);
+        let frame1 = spinner_char(1);
+        let frame_wrap = spinner_char(SPINNER_FRAMES.len() as u64);
+
+        assert_ne!(frame0, frame1, "Adjacent frames should differ");
+        assert_eq!(frame0, frame_wrap, "Should wrap around");
+    }
+
+    // --- Error toast tests ---
+
+    #[test]
+    fn test_error_toast_renders() {
+        with_frame!(80, 24, |frame| {
+            render_error_toast(
+                &mut frame,
+                Rect::new(0, 0, 80, 24),
+                "Database is busy",
+                red_bg(),
+                white(),
+            );
+
+            // Toast should be at bottom-right. Check row 22 (24-1-1).
+            let y = 22u16;
+            let has_content = (40..80u16).any(|x| {
+                let cell = frame.buffer.get(x, y).unwrap();
+                !cell.is_empty()
+            });
+            assert!(has_content, "Expected error toast at bottom-right");
+        });
+    }
+
+    #[test]
+    fn test_error_toast_empty_message_noop() {
+        with_frame!(80, 24, |frame| {
+            render_error_toast(&mut frame, Rect::new(0, 0, 80, 24), "", red_bg(), white());
+
+            // No content should be rendered.
+            let has_content = (0..80u16).any(|x| {
+                (0..24u16).any(|y| {
+                    let cell = frame.buffer.get(x, y).unwrap();
+                    !cell.is_empty()
+                })
+            });
+            assert!(!has_content, "Empty message should render nothing");
+        });
+    }
+
+    #[test]
+    fn test_error_toast_truncates_long_message() {
+        with_frame!(80, 24, |frame| {
+            let long_msg = "A".repeat(200);
+            // Should not panic and should truncate.
+            render_error_toast(
+                &mut frame,
+                Rect::new(0, 0, 80, 24),
+                &long_msg,
+                red_bg(),
+                white(),
+            );
+        });
+    }
+
+    // --- Help overlay tests ---
+
+    #[test]
+    fn test_help_overlay_renders_border() {
+        with_frame!(80, 24, |frame| {
+            let registry = build_registry();
+            render_help_overlay(
+                &mut frame,
+                Rect::new(0, 0, 80, 24),
+                &registry,
+                &Screen::Dashboard,
+                gray(),
+                white(),
+                gray(),
+                0,
+            );
+
+            // The overlay should have non-empty cells in the center area.
+            let has_content = (20..60u16).any(|x| {
+                (8..16u16).any(|y| {
+                    let cell = frame.buffer.get(x, y).unwrap();
+                    !cell.is_empty()
+                })
+            });
+            assert!(has_content, "Expected help overlay in center area");
+        });
+    }
+
+    #[test]
+    fn test_help_overlay_tiny_terminal_noop() {
+        with_frame!(15, 4, |frame| {
+            let registry = build_registry();
+            // Too small — should be a no-op.
+            render_help_overlay(
+                &mut frame,
+                Rect::new(0, 0, 15, 4),
+                &registry,
+                &Screen::Dashboard,
+                gray(),
+                white(),
+                gray(),
+                0,
+            );
+        });
+    }
+
+    // --- Truncation helper tests ---
+
+    #[test]
+    fn test_truncate_breadcrumb_fits() {
+        let crumbs = vec!["A", "B"];
+        let result = truncate_breadcrumb_left(&crumbs, " > ", 100);
+        // When it doesn't need truncation, this function is not called
+        // in practice, but it should still work.
+        assert!(result.contains("..."), "Should always add ellipsis");
+    }
+
+    #[test]
+    fn test_truncate_breadcrumb_single_entry() {
+        let crumbs = vec!["Dashboard"];
+        let result = truncate_breadcrumb_left(&crumbs, " > ", 5);
+        assert_eq!(result, "...");
+    }
+
+    #[test]
+    fn test_truncate_breadcrumb_shows_last_entries() {
+        let crumbs = vec!["Dashboard", "Issues", "Issue Detail"];
+        let result = truncate_breadcrumb_left(&crumbs, " > ", 30);
+        assert!(result.starts_with("..."));
+        assert!(result.contains("Issue Detail"));
+    }
+}

crates/lore-tui/src/view/mod.rs

@@ -0,0 +1,185 @@
+#![allow(dead_code)] // Phase 1: screen content renders added in Phase 2+
+
+//! Top-level view dispatch for the lore TUI.
+//!
+//! [`render_screen`] is the entry point called from `LoreApp::view()`.
+//! It composes the layout: breadcrumb bar, screen content area, status
+//! bar, and optional overlays (help, error toast).
+
+pub mod common;
+
+use ftui::layout::{Constraint, Flex};
+use ftui::render::cell::PackedRgba;
+use ftui::render::frame::Frame;
+
+use crate::app::LoreApp;
+
+use common::{
+    render_breadcrumb, render_error_toast, render_help_overlay, render_loading, render_status_bar,
+};
+
+// ---------------------------------------------------------------------------
+// Colors (hardcoded Flexoki palette — will use Theme in Phase 2)
+// ---------------------------------------------------------------------------
+
+const TEXT: PackedRgba = PackedRgba::rgb(0xCE, 0xCD, 0xC3); // tx
+const TEXT_MUTED: PackedRgba = PackedRgba::rgb(0x87, 0x87, 0x80); // tx-2
+const BG_SURFACE: PackedRgba = PackedRgba::rgb(0x28, 0x28, 0x24); // bg-2
+const ACCENT: PackedRgba = PackedRgba::rgb(0xDA, 0x70, 0x2C); // orange
+const ERROR_BG: PackedRgba = PackedRgba::rgb(0xAF, 0x3A, 0x29); // red
+const ERROR_FG: PackedRgba = PackedRgba::rgb(0xCE, 0xCD, 0xC3); // tx
+const BORDER: PackedRgba = PackedRgba::rgb(0x87, 0x87, 0x80); // tx-2
+
+// ---------------------------------------------------------------------------
+// render_screen
+// ---------------------------------------------------------------------------
+
+/// Top-level view dispatch: composes breadcrumb + content + status bar + overlays.
+///
+/// Called from `LoreApp::view()`. The layout is:
+/// ```text
+/// +-----------------------------------+
+/// | Breadcrumb (1 row)                |
+/// +-----------------------------------+
+/// |                                   |
+/// | Screen content (fill)             |
+/// |                                   |
+/// +-----------------------------------+
+/// | Status bar (1 row)                |
+/// +-----------------------------------+
+/// ```
+///
+/// Overlays (help, error toast) render on top of existing content.
+pub fn render_screen(frame: &mut Frame<'_>, app: &LoreApp) {
+    let bounds = frame.bounds();
+    if bounds.width < 3 || bounds.height < 3 {
+        return; // Terminal too small to render anything useful.
+    }
+
+    // Split vertically: breadcrumb (1) | content (fill) | status bar (1).
+    let regions = Flex::vertical()
+        .constraints([
+            Constraint::Fixed(1), // breadcrumb
+            Constraint::Fill,     // content
+            Constraint::Fixed(1), // status bar
+        ])
+        .split(bounds);
+
+    let breadcrumb_area = regions[0];
+    let content_area = regions[1];
+    let status_area = regions[2];
+
+    let screen = app.navigation.current();
+
+    // --- Breadcrumb ---
+    render_breadcrumb(frame, breadcrumb_area, &app.navigation, TEXT, TEXT_MUTED);
+
+    // --- Screen content ---
+    let load_state = app.state.load_state.get(screen);
+    // tick=0 placeholder — animation wired up when Msg::Tick increments a counter.
+    render_loading(frame, content_area, load_state, TEXT, TEXT_MUTED, 0);
+
+    // Per-screen content dispatch (Phase 2+).
+    // match screen {
+    //     Screen::Dashboard => ...,
+    //     Screen::IssueList => ...,
+    //     ...
+    // }
+
+    // --- Status bar ---
+    render_status_bar(
+        frame,
+        status_area,
+        &app.command_registry,
+        screen,
+        &app.input_mode,
+        BG_SURFACE,
+        TEXT,
+        ACCENT,
+    );
+
+    // --- Overlays (render last, on top of everything) ---
+
+    // Error toast.
+    if let Some(ref error_msg) = app.state.error_toast {
+        render_error_toast(frame, bounds, error_msg, ERROR_BG, ERROR_FG);
+    }
+
+    // Help overlay.
+    if app.state.show_help {
+        render_help_overlay(
+            frame,
+            bounds,
+            &app.command_registry,
+            screen,
+            BORDER,
+            TEXT,
+            TEXT_MUTED,
+            0, // scroll_offset — tracked in future phase
+        );
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::app::LoreApp;
+    use ftui::render::grapheme_pool::GraphemePool;
+
+    macro_rules! with_frame {
+        ($width:expr, $height:expr, |$frame:ident| $body:block) => {{
+            let mut pool = GraphemePool::new();
+            let mut $frame = Frame::new($width, $height, &mut pool);
+            $body
+        }};
+    }
+
+    #[test]
+    fn test_render_screen_does_not_panic() {
+        with_frame!(80, 24, |frame| {
+            let app = LoreApp::new();
+            render_screen(&mut frame, &app);
+        });
+    }
+
+    #[test]
+    fn test_render_screen_tiny_terminal_noop() {
+        with_frame!(2, 2, |frame| {
+            let app = LoreApp::new();
+            render_screen(&mut frame, &app);
+            // Should not panic — early return for tiny terminals.
+        });
+    }
+
+    #[test]
+    fn test_render_screen_with_error_toast() {
+        with_frame!(80, 24, |frame| {
+            let mut app = LoreApp::new();
+            app.state.set_error("test error".into());
+            render_screen(&mut frame, &app);
+            // Should render without panicking.
+        });
+    }
+
+    #[test]
+    fn test_render_screen_with_help_overlay() {
+        with_frame!(80, 24, |frame| {
+            let mut app = LoreApp::new();
+            app.state.show_help = true;
+            render_screen(&mut frame, &app);
+            // Should render without panicking.
+        });
+    }
+
+    #[test]
+    fn test_render_screen_narrow_terminal() {
+        with_frame!(20, 5, |frame| {
+            let app = LoreApp::new();
+            render_screen(&mut frame, &app);
+        });
+    }
+}

src/cli/commands/who.rs

@@ -13,6 +13,20 @@ use crate::core::paths::get_db_path;
 use crate::core::project::resolve_project;
 use crate::core::time::{ms_to_iso, now_ms, parse_since};
 
+// ─── Decay Math ─────────────────────────────────────────────────────────────
+
+/// Exponential half-life decay: R = 2^(-t/h)
+/// Returns 1.0 at elapsed=0, 0.5 at elapsed=half_life, 0.0 if half_life=0.
+#[allow(dead_code)] // Used by bd-13q8 (decay aggregation)
+fn half_life_decay(elapsed_ms: i64, half_life_days: u32) -> f64 {
+    let days = (elapsed_ms as f64 / 86_400_000.0).max(0.0);
+    let hl = f64::from(half_life_days);
+    if hl <= 0.0 {
+        return 0.0;
+    }
+    2.0_f64.powf(-days / hl)
+}
+
 // ─── Mode Discrimination ────────────────────────────────────────────────────
 
 /// Determines which query mode to run based on args.
@@ -3568,6 +3582,7 @@ mod tests {
             author_weight: 5,
             reviewer_weight: 30,
             note_bonus: 1,
+            ..ScoringConfig::default()
         };
         let result = query_expert(&conn, "src/app.rs", None, 0, 20, &flipped, false).unwrap();
         assert_eq!(result.experts[0].username, "the_reviewer");
@@ -3690,4 +3705,38 @@ mod tests {
             );
         }
     }
+
+    // ─── half_life_decay tests ────────────────────────────────────────────────
+
+    #[test]
+    fn test_half_life_decay_math() {
+        let hl_180 = 180;
+        // At t=0, full retention
+        assert!((half_life_decay(0, hl_180) - 1.0).abs() < f64::EPSILON);
+        // At t=half_life, exactly 0.5
+        let one_hl_ms = 180 * 86_400_000_i64;
+        assert!((half_life_decay(one_hl_ms, hl_180) - 0.5).abs() < 1e-10);
+        // At t=2*half_life, exactly 0.25
+        assert!((half_life_decay(2 * one_hl_ms, hl_180) - 0.25).abs() < 1e-10);
+        // Negative elapsed clamped to 0 -> 1.0
+        assert!((half_life_decay(-1000, hl_180) - 1.0).abs() < f64::EPSILON);
+        // Zero half-life -> 0.0 (div-by-zero guard)
+        assert!((half_life_decay(86_400_000, 0)).abs() < f64::EPSILON);
+    }
+
+    #[test]
+    fn test_score_monotonicity_by_age() {
+        let mut seed: u64 = 42;
+        let hl = 90_u32;
+        for _ in 0..50 {
+            seed = seed.wrapping_mul(6_364_136_223_846_793_005).wrapping_add(1);
+            let newer_ms = (seed % 100_000_000) as i64;
+            seed = seed.wrapping_mul(6_364_136_223_846_793_005).wrapping_add(1);
+            let older_ms = newer_ms + (seed % 500_000_000) as i64;
+            assert!(
+                half_life_decay(older_ms, hl) <= half_life_decay(newer_ms, hl),
+                "Monotonicity violated: decay({older_ms}) > decay({newer_ms})"
+            );
+        }
+    }
 }

src/core/config.rs

@@ -164,6 +164,38 @@ pub struct ScoringConfig {
     /// Bonus points per individual inline review comment (DiffNote).
     #[serde(rename = "noteBonus")]
     pub note_bonus: i64,
+
+    /// Points for being assigned as reviewer (without substantive notes).
+    #[serde(rename = "reviewerAssignmentWeight")]
+    pub reviewer_assignment_weight: i64,
+
+    /// Half-life in days for author contribution decay.
+    #[serde(rename = "authorHalfLifeDays")]
+    pub author_half_life_days: u32,
+
+    /// Half-life in days for reviewer participation decay.
+    #[serde(rename = "reviewerHalfLifeDays")]
+    pub reviewer_half_life_days: u32,
+
+    /// Half-life in days for reviewer-assignment-only decay.
+    #[serde(rename = "reviewerAssignmentHalfLifeDays")]
+    pub reviewer_assignment_half_life_days: u32,
+
+    /// Half-life in days for note/comment decay.
+    #[serde(rename = "noteHalfLifeDays")]
+    pub note_half_life_days: u32,
+
+    /// Multiplier applied to closed (not merged) MRs.
+    #[serde(rename = "closedMrMultiplier")]
+    pub closed_mr_multiplier: f64,
+
+    /// Minimum character count for a reviewer note to be "substantive".
+    #[serde(rename = "reviewerMinNoteChars")]
+    pub reviewer_min_note_chars: u32,
+
+    /// Usernames to exclude from scoring (e.g. bots).
+    #[serde(rename = "excludedUsernames")]
+    pub excluded_usernames: Vec<String>,
 }
 
 impl Default for ScoringConfig {
@@ -172,6 +204,14 @@ impl Default for ScoringConfig {
             author_weight: 25,
             reviewer_weight: 10,
             note_bonus: 1,
+            reviewer_assignment_weight: 3,
+            author_half_life_days: 180,
+            reviewer_half_life_days: 90,
+            reviewer_assignment_half_life_days: 45,
+            note_half_life_days: 45,
+            closed_mr_multiplier: 0.5,
+            reviewer_min_note_chars: 20,
+            excluded_usernames: Vec::new(),
         }
     }
 }
@@ -287,6 +327,51 @@ fn validate_scoring(scoring: &ScoringConfig) -> Result<()> {
             details: "scoring.noteBonus must be >= 0".to_string(),
         });
     }
+    if scoring.reviewer_assignment_weight < 0 {
+        return Err(LoreError::ConfigInvalid {
+            details: "scoring.reviewerAssignmentWeight must be >= 0".to_string(),
+        });
+    }
+
+    for (field, value) in [
+        ("authorHalfLifeDays", scoring.author_half_life_days),
+        ("reviewerHalfLifeDays", scoring.reviewer_half_life_days),
+        (
+            "reviewerAssignmentHalfLifeDays",
+            scoring.reviewer_assignment_half_life_days,
+        ),
+        ("noteHalfLifeDays", scoring.note_half_life_days),
+    ] {
+        if value == 0 || value > 3650 {
+            return Err(LoreError::ConfigInvalid {
+                details: format!("scoring.{field} must be > 0 and <= 3650"),
+            });
+        }
+    }
+
+    if !scoring.closed_mr_multiplier.is_finite()
+        || scoring.closed_mr_multiplier <= 0.0
+        || scoring.closed_mr_multiplier > 1.0
+    {
+        return Err(LoreError::ConfigInvalid {
+            details: "scoring.closedMrMultiplier must be finite and in (0.0, 1.0]".to_string(),
+        });
+    }
+
+    if scoring.reviewer_min_note_chars > 4096 {
+        return Err(LoreError::ConfigInvalid {
+            details: "scoring.reviewerMinNoteChars must be <= 4096".to_string(),
+        });
+    }
+
+    for username in &scoring.excluded_usernames {
+        if username.is_empty() {
+            return Err(LoreError::ConfigInvalid {
+                details: "scoring.excludedUsernames entries must be non-empty".to_string(),
+            });
+        }
+    }
+
     Ok(())
 }
 
@@ -543,6 +628,78 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_config_validation_rejects_zero_half_life() {
+        let mut cfg = ScoringConfig::default();
+        assert!(validate_scoring(&cfg).is_ok());
+        cfg.author_half_life_days = 0;
+        assert!(validate_scoring(&cfg).is_err());
+        cfg.author_half_life_days = 180;
+        cfg.reviewer_half_life_days = 0;
+        assert!(validate_scoring(&cfg).is_err());
+        cfg.reviewer_half_life_days = 90;
+        cfg.closed_mr_multiplier = 0.0;
+        assert!(validate_scoring(&cfg).is_err());
+        cfg.closed_mr_multiplier = 1.5;
+        assert!(validate_scoring(&cfg).is_err());
+        cfg.closed_mr_multiplier = 1.0;
+        assert!(validate_scoring(&cfg).is_ok());
+    }
+
+    #[test]
+    fn test_config_validation_rejects_absurd_half_life() {
+        let mut cfg = ScoringConfig::default();
+        cfg.author_half_life_days = 5000; // > 3650 cap
+        assert!(validate_scoring(&cfg).is_err());
+        cfg.author_half_life_days = 3650; // boundary: valid
+        assert!(validate_scoring(&cfg).is_ok());
+        cfg.reviewer_min_note_chars = 5000; // > 4096 cap
+        assert!(validate_scoring(&cfg).is_err());
+        cfg.reviewer_min_note_chars = 4096; // boundary: valid
+        assert!(validate_scoring(&cfg).is_ok());
+    }
+
+    #[test]
+    fn test_config_validation_rejects_nan_multiplier() {
+        let mut cfg = ScoringConfig::default();
+        cfg.closed_mr_multiplier = f64::NAN;
+        assert!(validate_scoring(&cfg).is_err());
+        cfg.closed_mr_multiplier = f64::INFINITY;
+        assert!(validate_scoring(&cfg).is_err());
+        cfg.closed_mr_multiplier = f64::NEG_INFINITY;
+        assert!(validate_scoring(&cfg).is_err());
+    }
+
+    #[test]
+    fn test_config_validation_rejects_negative_assignment_weight() {
+        let mut cfg = ScoringConfig::default();
+        cfg.reviewer_assignment_weight = -1;
+        assert!(validate_scoring(&cfg).is_err());
+    }
+
+    #[test]
+    fn test_config_validation_rejects_empty_excluded_username() {
+        let mut cfg = ScoringConfig::default();
+        cfg.excluded_usernames = vec!["".to_string()];
+        assert!(validate_scoring(&cfg).is_err());
+    }
+
+    #[test]
+    fn test_scoring_config_defaults() {
+        let cfg = ScoringConfig::default();
+        assert_eq!(cfg.author_weight, 25);
+        assert_eq!(cfg.reviewer_weight, 10);
+        assert_eq!(cfg.note_bonus, 1);
+        assert_eq!(cfg.reviewer_assignment_weight, 3);
+        assert_eq!(cfg.author_half_life_days, 180);
+        assert_eq!(cfg.reviewer_half_life_days, 90);
+        assert_eq!(cfg.reviewer_assignment_half_life_days, 45);
+        assert_eq!(cfg.note_half_life_days, 45);
+        assert!((cfg.closed_mr_multiplier - 0.5).abs() < f64::EPSILON);
+        assert_eq!(cfg.reviewer_min_note_chars, 20);
+        assert!(cfg.excluded_usernames.is_empty());
+    }
+
     #[test]
     fn test_minimal_config_includes_default_project_when_set() {
         let config = MinimalConfig {