Surface the TUI's blocking dialogs in chat, and let them be answered there

[xerhab]

Second follow-up to #317 — the remaining routine reason to switch to terminal mode.

The problem

Claude Code blocks a turn on two dialogs the chat could not see, because neither has a hook to intercept it and neither writes anything to the transcript:

 Bash command                       │   Claude has written up a plan and is ready
                                    │   to execute. Would you like to proceed?
   touch /tmp/marker                │
   Create marker file in /tmp       │   ❯ 1. Yes, and use auto mode
                                    │     2. Yes, manually approve edits
 Do you want to proceed?            │     3. No, refine with Ultraplan …
 ❯ 1. Yes                           │     4. Tell Claude what to change
   2. Yes, and always allow …       │
   3. No                            │

And it's worse than invisible: while a dialog is up the pane shows neither the "esc to interrupt" hint nor the mode footer, so paneBusy reads False and every surface labelled the session idle. A session actually blocked on a human read as finished — so you'd only discover it by opening the terminal, which is also the only place you could answer.

The change

• parse_pane_prompt reads the dialog off the same capture as the mode marker → {prompt, options:[{number,label,selected}], detail}, reported as session.panePrompt.
  • Nothing keys on the wording (it differs per dialog, and will drift). A run of lines is a dialog only with all of: options numbered 1..N (N≥2) in order, exactly one carrying the ❯ cursor, a ? line directly above, and no mode footer below. That last one is the discriminator — the footer rides the composer, which a dialog replaces, so its absence separates a live dialog from transcript text shaped like one.
  • detail is the fenced block above the question — the command plus its description, or the plan body. Blanks never close it, a rule does: a permission dialog's block sits directly above the question while a plan's sits one rule further up, and one walk has to find both.
• Rendered in the chat's existing pending-question box (a session is never blocked on both — one blocks in the ask.py hook, the other in the TUI) with the context and numbered picks, the TUI's own cursor position marked.
• Answerable: POST .../sessions/<id>/pane-prompt {optionNumber} → answerPanePrompt → the agent types that digit. The agent re-reads the pane first and drops the answer unless the number is on screen right now — the click was made against a beat-old heartbeat, and a bare digit typed into a live composer silently prepends itself to the operator's next message.
• Both liveStates (dashboard + sessions) check it ahead of the busy read, so the card reads "waiting for your answer" rather than idle; Stop is hidden while a dialog waits, same reasoning as XERK-21.

Verification

• Agent 803 + turma 634 suites green. The parser and answer-command tests are driven by verbatim tmux capture-pane output captured from two live dialogs (a real Bash permission request and a real plan approval on Claude Code 2.1.220), not hand-written strings — the wordings, glyphs and blank-line placement are the contract, and inventing them is how a parser passes its tests and fails a pane. Negative controls cover an idle composer showing a numbered list with a "?" above it, missing cursor, numbering not starting at 1, and a single option.
• End-to-end in Chromium against a booted hub: the dialog renders with its context and picks, clicking option 2 queues answerPanePrompt {optionNumber: 2} on the agent's command queue, the sidebar header reports "1 running · 1 waiting on you" and the card reads "waiting for your answer" (it read plain idle before this change). Checked light, dark, and 390px.

Notes

• Android decodes the new field away today (safe degrade — such a session still reads idle there); gap recorded in android/PARITY.md.
• CLAUDE.md is over its own 150k budget (161k on main before this PR, ~163k after). Not introduced here and not something I wanted to fold into this change silently — worth a consolidation pass of its own.