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.

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> },
 }
 
 // ---------------------------------------------------------------------------