feat(cli): add 'lore related' semantic similarity command (bd-8con)

Adds 'lore related' / 'lore similar' command for discovering semantically
related issues and MRs using vector embeddings.

Two modes:
- Entity mode: find entities similar to a specific issue/MR
- Query mode: embed free text and find matching entities

Includes distance-to-similarity conversion, label intersection,
human and robot output formatters, and 11 unit tests.

crates/lore-tui/src/app/tests.rs

@@ -377,3 +377,120 @@ fn test_sync_completed_from_bootstrap_resets_navigation_and_state() {
     assert_eq!(app.navigation.depth(), 1);
     assert!(!app.state.bootstrap.sync_started);
 }
+
+#[test]
+fn test_sync_completed_flushes_entity_caches() {
+    use crate::message::EntityKey;
+    use crate::state::issue_detail::{IssueDetailData, IssueMetadata};
+    use crate::state::mr_detail::{MrDetailData, MrMetadata};
+    use crate::state::{CachedIssuePayload, CachedMrPayload};
+    use crate::view::common::cross_ref::CrossRef;
+
+    let mut app = test_app();
+
+    // Populate caches with dummy data.
+    let issue_key = EntityKey::issue(1, 42);
+    app.state.issue_cache.put(
+        issue_key,
+        CachedIssuePayload {
+            data: IssueDetailData {
+                metadata: IssueMetadata {
+                    iid: 42,
+                    project_path: "g/p".into(),
+                    title: "Test".into(),
+                    description: String::new(),
+                    state: "opened".into(),
+                    author: "alice".into(),
+                    assignees: vec![],
+                    labels: vec![],
+                    milestone: None,
+                    due_date: None,
+                    created_at: 0,
+                    updated_at: 0,
+                    web_url: String::new(),
+                    discussion_count: 0,
+                },
+                cross_refs: Vec::<CrossRef>::new(),
+            },
+            discussions: vec![],
+        },
+    );
+
+    let mr_key = EntityKey::mr(1, 99);
+    app.state.mr_cache.put(
+        mr_key,
+        CachedMrPayload {
+            data: MrDetailData {
+                metadata: MrMetadata {
+                    iid: 99,
+                    project_path: "g/p".into(),
+                    title: "MR".into(),
+                    description: String::new(),
+                    state: "opened".into(),
+                    draft: false,
+                    author: "bob".into(),
+                    assignees: vec![],
+                    reviewers: vec![],
+                    labels: vec![],
+                    source_branch: "feat".into(),
+                    target_branch: "main".into(),
+                    merge_status: String::new(),
+                    created_at: 0,
+                    updated_at: 0,
+                    merged_at: None,
+                    web_url: String::new(),
+                    discussion_count: 0,
+                    file_change_count: 0,
+                },
+                cross_refs: Vec::<CrossRef>::new(),
+                file_changes: vec![],
+            },
+            discussions: vec![],
+        },
+    );
+
+    assert_eq!(app.state.issue_cache.len(), 1);
+    assert_eq!(app.state.mr_cache.len(), 1);
+
+    // Sync completes — caches should be flushed.
+    app.update(Msg::SyncCompleted { elapsed_ms: 500 });
+
+    assert!(
+        app.state.issue_cache.is_empty(),
+        "issue cache should be flushed after sync"
+    );
+    assert!(
+        app.state.mr_cache.is_empty(),
+        "MR cache should be flushed after sync"
+    );
+}
+
+#[test]
+fn test_sync_completed_refreshes_current_detail_view() {
+    use crate::message::EntityKey;
+    use crate::state::LoadState;
+
+    let mut app = test_app();
+
+    // Navigate to an issue detail screen.
+    let key = EntityKey::issue(1, 42);
+    app.update(Msg::NavigateTo(Screen::IssueDetail(key)));
+
+    // Simulate load completion so LoadState goes to Idle.
+    app.state.set_loading(
+        Screen::IssueDetail(EntityKey::issue(1, 42)),
+        LoadState::Idle,
+    );
+
+    // Sync completes while viewing the detail.
+    app.update(Msg::SyncCompleted { elapsed_ms: 300 });
+
+    // The detail screen should have been set to Refreshing.
+    assert_eq!(
+        *app.state
+            .load_state
+            .get(&Screen::IssueDetail(EntityKey::issue(1, 42))),
+        LoadState::Refreshing,
+        "detail view should refresh after sync"
+    );
+}

crates/lore-tui/src/app/update.rs

@@ -542,6 +542,11 @@ impl LoreApp {
             Msg::SyncCompleted { elapsed_ms } => {
                 self.state.sync.complete(elapsed_ms);
 
+                // Flush entity caches — sync may have updated any entity's
+                // metadata, discussions, or cross-refs in the DB.
+                self.state.issue_cache.clear();
+                self.state.mr_cache.clear();
+
                 // If we came from Bootstrap, replace nav history with Dashboard.
                 if *self.navigation.current() == Screen::Bootstrap {
                     self.state.bootstrap.sync_started = false;
@@ -557,6 +562,19 @@ impl LoreApp {
                     self.state.set_loading(dashboard.clone(), load_state);
                     let _handle = self.supervisor.submit(TaskKey::LoadScreen(dashboard));
                 }
+
+                // If currently on a detail view, refresh it so the user sees
+                // updated data without navigating away and back.
+                let current = self.navigation.current().clone();
+                match &current {
+                    Screen::IssueDetail(_) | Screen::MrDetail(_) => {
+                        self.state
+                            .set_loading(current.clone(), LoadState::Refreshing);
+                        let _handle = self.supervisor.submit(TaskKey::LoadScreen(current));
+                    }
+                    _ => {}
+                }
+
                 Cmd::none()
             }
             Msg::SyncCancelled => {