Console: project AI panel — collab agent chat

[hevayo]

Feature

A right-hand Agent Chat panel available on every project page (overview, spec, builds, deployments): send a message → a room-scoped collab turn (#86 phase 4) — the agent joins the project's spec room as a live peer, narrates in the panel, and its file edits appear live in the shared doc (visible to anyone in the spec workspace). Rebuilds the legacy console's ChatPanel experience on the new stack.

Decisions (grilled 2026-07-08)

1. Placement: right-hand panel, 380px, content shrinks (no overlay); Sparkles toggle in the header, project routes only; mounted in AppLayout beside the Outlet (the spec route bypasses ProjectLayout).
2. Legacy experience kept: user/assistant bubbles, tool cards (verb + filename chip + status), error bubbles, thinking dots, Sparkles empty-state greeting, per-project conversation (uuid in localStorage), rehydrate from GET /agents/{conv}/messages, re-attach to a running turn on mount, input disabled while a turn runs, 409 → inline error.
3. Collab-first internals (delta from legacy): turns are collab: true — no client-side file folding, snapshot seeding, or spec-page mirroring; the room IS the file surface. Panel = narration + tool cards.
4. Available on all project pages (not requirements-tab-gated like legacy); useCase: requirements-chat v1.
5. Not copied from legacy: always-mounted width-0 collapse, hardcoded rgba colors, markdown-lite renderer, MOCK-tagged layout wiring.
6. Ephemerality accepted for now: agent edits live in the room only; the phase-3 committer (next slice on feature-collab-with-agents) makes them durable before the integration PR to aep-rewrite.

Lands on feature-collab-with-agents (not aep-rewrite) per the #86 branch strategy.

Related: #86 (phase 4 + design comments), ex-PR #128 (agents-as-peers), #113/#80 (spec workspace).

[hevayo]

Built and verified live — commit ab2a349 on feature-collab-with-agents.

Implementation notes beyond the grilled decisions:

• Contract gained the turn READ surface frontend-first (GET /turns/{turnId}, /turns/active 200|204, /turns/{turnId}/stream as text/event-stream, + TurnStatus) — aep-api already served all three uncontracted; the panel's SSE attach rides the generated client (parseAs: "stream"), keeping the no-raw-fetch rule.
• Store is useSyncExternalStore over a localStorage-backed per-project log (legacy chatStore simplified); re-attach drops the turn's streamed output and replays from 0.
• Live verification on the deployed stack, from the panel on the spec workspace: agent avatar joined, tool cards folded (including a red failed-op card when the agent first tried a specs/-prefixed path, then the green retry — the room key scheme teaching the agent in real time), narration streamed, and the doc updated live in the same browser. Mock mode drives the full panel incl. a fail scenario.

Screenshot: 130-agent-chat-live.png (repo root, untracked).

Observed polish candidates for later (not blocking): agent narration is terse ("Done.") — steering prompt could ask for a one-line summary; failed-op cards could truncate long error text with a tooltip.