Quick-message a task's session: a sends headlessly, A attaches

[MJohnson459]

Quick-message a task's session without leaving the cockpit

Saying one sentence to an agent cost a full attach round-trip: suspend the
TUI, type, navigate back, ctrl-C. That price is paid on the cheapest
interaction there is — answering a needs-input question, adding a line of
review feedback — so it was routinely not paid at all.

a now collects one line in the same inline input the refine note uses and
sends it into the task's recorded session headlessly, fire-and-forget; the
TUI never suspends. The interactive jump-in moves to A, the same
lowercase-quick, uppercase-interactive pairing as r/R.

Agents declare the capability with a new optional message verb carrying
both {session} and {prompt_file}, built in for claude as its resume
plus -p. The near-duplication between those two verb bodies is deliberate
and not factored: a verb is an opaque per-agent contract, which is exactly
what lets codex define no message and degrade one verb at a time rather
than losing its jump-in with it.

The key applies to the three states whose session is open and between turns
— needs-input, review, waiting — and refuses the rest: running and
refining are mid-turn with no injection channel, and stalled has a dead
session, where a headless resume would restart the work with no tracked pid
and no session row, invisible to the reconciler. A liveness probe refuses a
session still running for the same reason. On a review or waiting task the
message is the rejection: RejectWork is applied before the send, so the
feedback is in the body and the event log first and a refused transition
sends nothing. There is no separate "just asking" mode — a second channel
that spoke to the agent without recording it would put the task's body and
its session out of step. A needs-input task transitions not at all; the
answer belongs to the transcript and the agent's own voro resume moves it.

The send borrows the refine round's detached-spawn plumbing (stamped prompt
and log in the runtime dir, launch-log breadcrumb, detached reaper), factored
out of spawn_expansion as spawn_logged, but records no session row and
tracks no pid: it joins a conversation Voro already knows about.

One knock-on: the new a/A slot would have pushed the cockpit key line to
eleven slots on a review row, past the ten §9 allows. d/D dispatch is now
advertised only where dispatch can act — ready or stalled — instead of on
any selection, which both restores the budget and stops the line offering a
verb whose only answer is the state it refuses.

DESIGN.md §6/§8/§9 and docs/agent-integration.md updated in the same change.

Verified: cargo test --workspace and cargo clippy --workspace --all-targets -- -D warnings pass. New tests cover the verb's placeholder
validation and its refusal of the launch placeholders, override_missing_verbs
reporting a dropped message, one-pass rendering of the two bindings, the
state gate, and the key itself driven against stub agents through a real
spawn: a review task's message rejects with feedback and lands in the launch
log, a needs-input task's sends with no transition, a live session is
refused, and a missing verb, a missing ref, and a missing session each report.
The TUI could not be driven under tmux here — this session's write guard
refuses the VORO_DB/XDG_CONFIG_HOME redirection the scratch harness needs
— so the key-line and key-map changes are covered by render tests instead.

Co-Authored-By: Claude Opus 5 noreply@anthropic.com
Claude-Session: https://claude.ai/code/session_01JWjypXGmxq2NXuChFfhRdi