bug(claude): a prompt whose absorption times out is left in the native composer, and every later delivery refuses it as a human draft #1350

What happened (2026-09-26, manager fleet, structured Claude sessions while they were busy)

1. ac_agents_prompt was sent to worker W1, a Claude session in the middle of a turn. It returned stage: absorption, code: absorption-timeout, promptWritten: true, enterWritten: false, and the message "did not visibly absorb the prompt and its composer could not be recovered" (disposition: do-not-retry).
2. The prompt text is now left in Claude's native composer, unsent.
3. Worker W4 has shown the same state since about 02:25Z. ac_agents_input_inspect returns nativeDraft.state: occupied and readinessReason: composer-occupied, while the Agent Code draft (ac_agents_draft_get) is empty. Every later ac_agents_prompt to W4 is refused as "prompt input is occupied by a human draft". That is four refusals across 25 minutes, and no human typed in that pane. The likely origin is an earlier manager prompt that stranded the same way, perhaps around the app restart.

Why it matters

• A failed delivery leaves our OWN text behind, and the gate then treats it as a human draft. The agent becomes unreachable for orchestration until someone clears the composer by hand, and nothing tells the sender that the "human draft" is its own stranded prompt.
• The stranded text is also submitted along with whatever the human types next.

Expected

• When absorption fails and recovery also fails, the delivery layer either (a) keeps a record that the composer holds its own stranded prompt, so it can reclaim it (clear it, then retry, or surface "your earlier prompt is stranded"), or (b) never leaves it behind. The composer clear and verify should happen before do-not-retry is reported.
• composer-occupied should say whether the occupant is known to be our own stranded write.

Evidence

• W1 ac_agents_prompt operation c7eb1822-1d65-423c-b2a5-6f83a98b4dff (outcome_unknown).
• W4 refusals: operations a0a85f4e, 6bc085b8, d2ceab7a, 5f9b16e0, plus ac_agents_input_inspect showing composer-occupied with an empty Agent Code draft.

Owner action for now: press Enter (to send) or Esc (to clear) in the affected panes.