fix(ui): save notes from tmux Ctrl-S input

[benvinegar]

Summary

• Normalize Ctrl-S note-saving input across raw control, CSI-u, and tmux control-mode encodings
• Prevent handled save/cancel shortcut keys from reaching the focused textarea
• Add regression coverage for CSI-u Ctrl-S input

Fixes #345

Testing

• bun run typecheck
• bun test
• tmux smoke: raw C-s saved a draft note without inserting 0x13
• tmux smoke: literal CSI-u ESC [ 115 ; 5 u saved a draft note without inserting 0x13 or 115;5u

This PR description was generated by Pi using OpenAI GPT-5 Codex

[greptile-apps]

Greptile Summary

Fixes Ctrl-S note saving when tmux forwards keyboard input using CSI-u encoding (\u001b[115;5u) by extracting a isSaveDraftNoteKey helper that normalises all three encodings (raw \u0013, key.ctrl + name, and CSI-u), and by adding explicit preventDefault/stopPropagation calls so the event never leaks into the focused textarea.

• keyboard.ts — new isSaveDraftNoteKey covers raw control, key.ctrl flag, and CSI-u sequence; also matches the literal string \"0x13\" via CTRL_S_HEX_LABEL which appears to be dead code.
• AgentInlineNote.tsx + useAppKeyboardShortcuts.ts — both now consume the key on match, preventing stray characters from reaching the textarea.
• AppHost.interactions.test.tsx — regression test added for the CSI-u path.

Confidence Score: 4/5

The change is safe to merge; the core CSI-u fix is correct and the new test exercises the added path end-to-end.

The CTRL_S_HEX_LABEL = "0x13" constant matches the 4-character text string "0x13" rather than any known terminal encoding, and the actual control character is already covered by CTRL_S. This is most likely dead code, but the misleading name and unexplained purpose leave a small gap in confidence.

src/ui/lib/keyboard.ts — the CTRL_S_HEX_LABEL clauses warrant a second look to confirm intent or remove them.

Important Files Changed

Filename	Overview
src/ui/lib/keyboard.ts	New isSaveDraftNoteKey correctly adds CSI-u detection, but also matches "0x13" as a literal string via CTRL_S_HEX_LABEL — the textual label of the control character, not any known terminal encoding — appears to be dead code or an accidental match.
src/ui/hooks/useAppKeyboardShortcuts.ts	Extracts inline Ctrl-S check into isSaveDraftNoteKey, adds consumeKey helper, and applies preventDefault/stopPropagation to both Escape and Ctrl-S note shortcuts — clean refactor with correct intent.
src/ui/components/panes/AgentInlineNote.tsx	Adds a isSaveDraftNoteKey guard inside the textarea key handler, consuming the event before it reaches the textarea so CSI-u Ctrl-S no longer inserts 115;5u into the note text.
src/ui/AppHost.interactions.test.tsx	Adds regression test for the CSI-u Ctrl-S path — verifies the note is saved and the draft label disappears without inserting stray characters.
CHANGELOG.md	Single changelog entry added for the tmux CSI-u Ctrl-S fix.

Sequence Diagram

sequenceDiagram
    participant T as Terminal/tmux
    participant AI as AgentInlineNote keyHandler
    participant KS as useAppKeyboardShortcuts
    participant TA as Textarea

    T->>AI: KeyEvent (raw 0x13 or CSI-u)
    AI->>AI: isSaveDraftNoteKey check
    alt Ctrl-S recognized in component
        AI->>AI: preventDefault + stopPropagation
        AI->>AI: draft.onSave()
        note over TA: event never reaches textarea
    else Escape in component
        AI->>AI: preventDefault + stopPropagation
        AI->>AI: draft.onCancel()
    else other key
        AI->>KS: propagate
        KS->>KS: isSaveDraftNoteKey check
        alt Ctrl-S in app shortcuts
            KS->>KS: consumeKey + saveDraftNote
        else Escape in app shortcuts
            KS->>KS: consumeKey + cancelDraftNote
        else other
            KS->>TA: propagate to textarea
        end
    end

Loading

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
src/ui/lib/keyboard.ts:28-29
`CTRL_S_HEX_LABEL` matches the literal 4-character ASCII string `"0x13"`, not the control character. The control character (`\u0013`) is already matched by `CTRL_S` on lines 24–25, so these two clauses are dead code unless some terminal or tmux mode actually emits the text string `"0x13"` as a key sequence. If no such encoding exists, these lines should be removed to avoid confusion; if they were added to handle a specific case, a comment explaining which encoding produces this string would prevent the next reader from assuming it is a typo.

_{Reviews (1): Last reviewed commit: "fix(ui): save notes from tmux Ctrl-S inp..." | Re-trigger Greptile}

[greptile-apps]

CTRL_S_HEX_LABEL matches the literal 4-character ASCII string "0x13", not the control character. The control character (\u0013) is already matched by CTRL_S on lines 24–25, so these two clauses are dead code unless some terminal or tmux mode actually emits the text string "0x13" as a key sequence. If no such encoding exists, these lines should be removed to avoid confusion; if they were added to handle a specific case, a comment explaining which encoding produces this string would prevent the next reader from assuming it is a typo.

Prompt To Fix With AI

This is a comment left during a code review.
Path: src/ui/lib/keyboard.ts
Line: 28-29

Comment:
`CTRL_S_HEX_LABEL` matches the literal 4-character ASCII string `"0x13"`, not the control character. The control character (`\u0013`) is already matched by `CTRL_S` on lines 24–25, so these two clauses are dead code unless some terminal or tmux mode actually emits the text string `"0x13"` as a key sequence. If no such encoding exists, these lines should be removed to avoid confusion; if they were added to handle a specific case, a comment explaining which encoding produces this string would prevent the next reader from assuming it is a typo.

How can I resolve this? If you propose a fix, please make it concise.

[benvinegar]

Good catch — the literal 0x13 fallback was speculative and not backed by the tmux smoke test. I removed it, leaving only raw Ctrl-S and CSI-u handling.

This comment was generated by Pi using OpenAI GPT-5 Codex