feat(claudbg-6t38,claudbg-trk3): add gg/G vim-style jump navigation in transcript

gg (double-g): jump to top of transcript via pending_g chord detection.
G (Shift+G): jump to bottom of transcript.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.beans/claudbg-6t38--tui-gg-jumps-to-top-of-transcript.md

@@ -1,10 +1,15 @@
 ---
 # claudbg-6t38
 title: 'TUI: gg jumps to top of transcript'
-status: todo
+status: completed
 type: feature
+priority: normal
 created_at: 2026-03-31T23:45:20Z
-updated_at: 2026-03-31T23:45:20Z
+updated_at: 2026-04-01T05:53:50Z
 ---
 
 Add gg (double-g) keybinding in the transcript view to jump to the top of the transcript (vim-style gg navigation). Requires buffering single 'g' keypress to detect the chord.
+
+## Summary of Changes
+
+Added `pending_g: bool` field to `AppState` (init to false). In `handle_transcript_event`, clear `pending_g` on any key that isn't 'g', then handle 'g': if `pending_g` was already set, scroll to top (gg); otherwise set `pending_g = true`.

.beans/claudbg-trk3--tui-shiftg-jumps-to-bottom-of-transcript.md

@@ -1,10 +1,15 @@
 ---
 # claudbg-trk3
 title: 'TUI: Shift+G jumps to bottom of transcript'
-status: todo
+status: completed
 type: feature
+priority: normal
 created_at: 2026-03-31T23:45:17Z
-updated_at: 2026-03-31T23:45:17Z
+updated_at: 2026-04-01T05:53:50Z
 ---
 
 Add Shift+G keybinding in the transcript view to jump to the bottom of the transcript (vim-style G navigation).
+
+## Summary of Changes
+
+Added `KeyCode::Char('G')` arm in `handle_transcript_event`: computes total rendered lines via `build_chat_lines` and sets `transcript_scroll` to `total_lines.saturating_sub(page_height)` — same clamping as PageDown, but jumps directly to bottom.

src/tui/screens/transcript.rs

@@ -536,6 +536,11 @@ pub fn handle_transcript_event(event: Event, state: &mut AppState) -> bool {
         return handle_search_input_event(key.code, state);
     }
 
+    // Clear the pending-g chord state on any key that is not 'g' itself.
+    if !matches!(key.code, KeyCode::Char('g')) {
+        state.pending_g = false;
+    }
+
     match key.code {
         // Toggle focus: ChatLog → SubagentsPanel → SearchInput → ChatLog.
         KeyCode::Tab => {
@@ -655,6 +660,23 @@ pub fn handle_transcript_event(event: Event, state: &mut AppState) -> bool {
                 false
             }
         }
+        // gg → jump to top of transcript (vim-style).
+        KeyCode::Char('g') => {
+            if std::mem::take(&mut state.pending_g) {
+                state.transcript_scroll = 0;
+            } else {
+                state.pending_g = true;
+            }
+            true
+        }
+        // Shift+G → jump to bottom of transcript (vim-style).
+        KeyCode::Char('G') => {
+            let total_lines =
+                build_chat_lines(&state.transcript_entries, state.color_enabled).len();
+            state.transcript_scroll =
+                total_lines.saturating_sub(state.transcript_page_height as usize);
+            true
+        }
         _ => false,
     }
 }

src/tui/state.rs

@@ -157,6 +157,11 @@ pub struct AppState {
     /// `None` means the user is not currently browsing history.
     pub filter_history_pos: Option<usize>,
 
+    // ── Keyboard chord state ─────────────────────────────────────────────────
+    /// Tracks whether a leading `g` keypress was seen, awaiting a second `g`
+    /// to complete the `gg` (jump-to-top) chord.  Cleared on any other key.
+    pub pending_g: bool,
+
     // ── Display ─────────────────────────────────────────────────────────────
     /// Whether color coding is enabled in transcript views.
     ///
@@ -174,7 +179,11 @@ impl AppState {
     /// Return the path to the filter history file: `~/.claude/claudbg.tui.history`.
     fn history_file_path() -> Option<PathBuf> {
         let home = std::env::var("HOME").ok()?;
-        Some(PathBuf::from(home).join(".claude").join("claudbg.tui.history"))
+        Some(
+            PathBuf::from(home)
+                .join(".claude")
+                .join("claudbg.tui.history"),
+        )
     }
 
     /// Load filter history lines from disk.
@@ -240,6 +249,7 @@ impl AppState {
             filter_active: String::new(),
             filter_history,
             filter_history_pos: None,
+            pending_g: false,
             color_enabled,
             should_quit: false,
         }