fix(terminal): stop Android autocorrect duplicating the typed line

xterm diffs the helper textarea with newValue.replace(oldValue, ''), which only works when the keyboard appended. SwiftKey/Gboard autocorrect on space deletes a word and inserts the corrected one, so xterm sent the whole value and then the inserted text again (testing the peompt + space became 'testing the peompttesting the prompt rompt '), and a multi-character delete was one DEL. The keyCode-229 controller now swaps in an edit-based diff against what was already sent.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JrzFKEdBLwVfu6ev2ZscJS

src/web/public/terminal-ui.js

@@ -1793,6 +1793,7 @@ Object.assign(CodemanApp.prototype, {
       this._keyCode229Recovery = window.CodemanKeyCode229Recovery?.create?.({
         textarea: this.terminal.textarea,
         emitRecovered: (data) => handleTerminalData(data),
+        getCompositionHelper: () => this.terminal?._core?._compositionHelper,
         isScreenReaderMode: () => this.terminal?.options?.screenReaderMode === true,
       });
     } catch {