feat(claudbg-e49f): add Home/End key bindings to jump to top/bottom of transcript

Home jumps to the top (scroll = 0) and End jumps to the bottom, mirroring
the existing gg/G vim-style bindings. Help modal updated to document both.

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

.beans/claudbg-e49f--tui-homeend-keys-jump-to-topbottom-of-transcript.md

@@ -1,10 +1,11 @@
 ---
 # claudbg-e49f
 title: 'TUI: Home/End keys jump to top/bottom of transcript'
-status: todo
+status: in-progress
 type: feature
+priority: normal
 created_at: 2026-04-01T06:11:02Z
-updated_at: 2026-04-01T06:11:02Z
+updated_at: 2026-04-01T06:16:58Z
 ---
 
 Add Home and End key bindings in the transcript screen to complement the existing gg/G vim-style bindings:\n- Home → jump to top of transcript (same as gg)\n- End  → jump to bottom of transcript (same as G)\n\nHandle in handle_transcript_event() in src/tui/screens/transcript.rs alongside the existing Char('g')/Char('G') cases.

src/tui/modals/help_modal.rs

@@ -16,7 +16,7 @@ use crate::tui::state::AppState;
 
 /// Dialog dimensions.
 const DIALOG_WIDTH: u16 = 32;
-const DIALOG_HEIGHT: u16 = 26;
+const DIALOG_HEIGHT: u16 = 28;
 
 /// Compute a centered [`Rect`] of the given size within `area`.
 fn centered_rect(width: u16, height: u16, area: Rect) -> Rect {
@@ -40,6 +40,8 @@ const HELP_TEXT: &str = "\
   Spc/PgDn  page down\n\
   \u{21e7}Spc/PgUp  page up\n\
   \u{2190}/\u{2192} h/l  scroll lr\n\
+  Home/gg   jump to top\n\
+  End/G     jump to bottom\n\
   Tab       cycle panes\n\
   Enter     open/select\n\
   Esc       go back\n\

src/tui/screens/transcript.rs

@@ -678,6 +678,19 @@ pub fn handle_transcript_event(event: Event, state: &mut AppState) -> bool {
                 false
             }
         }
+        // Home → jump to top of transcript.
+        KeyCode::Home => {
+            state.transcript_scroll = 0;
+            true
+        }
+        // End → jump to bottom of transcript.
+        KeyCode::End => {
+            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
+        }
         // gg → jump to top of transcript (vim-style).
         KeyCode::Char('g') => {
             if std::mem::take(&mut state.pending_g) {