[blindwolf90]

Summary

Adds an isolated ?studio dry-run UI with only COO and Engineer: claim-request menu, desk report, approve/return actions, blocked hand raise, and a persistent bridge-status banner. All actions use a local mock handler; no real system is connected.

Existing event types and state machine

The existing protocol accepts only join / status / tool / message / task / leave / reset. join creates teams/agents, status changes agent state, tool normally enters working, message creates message effects, task updates the team task, leave enters offline, and reset clears the world. POST /events normalizes and applies events; GET /stream sends a snapshot followed by event/effect updates. This PR does not change the server or shared/protocol.js.

New front-end-only dry-run events

• claim_confirmed {agent, task_id, task_title, source}: assign the simulated task and walk Engineer to COO and back.
• claim_rejected {agent, reason}: show the rejection reason.
• blocked {agent, task_id, reason}: raise Engineer's hand; opening the reason does not clear it.
• report_ready {agent, task_id, report_url|report_local, summary}: place a report on the desk for review.
• review_result {task_id, result, note}: remove an approved report or mark a returned report red.
• bridge_status {mode, connected, last_update_ts, note}: update the persistent mode/connectivity/staleness banner.

Local action intents use POST-shaped /actions requests for claim_request and review, but src/studio/transport.ts resolves them locally and never sends them over the network. Only confirmation events complete a claim or review.

Validation

• npm test — 17/17 PASS (7 new tests).
• npm run build — TypeScript and Vite production build PASS.
• node sim/dry-run.js — deterministic sequence including rejection and blockage; output saved.
• node scripts/studio-browser.mjs — Chrome CDP mobile emulation at 390×844, real coordinate clicks, 44px targets, no horizontal overflow or external resource origins.

Evidence: docs/eng-160/evidence/ contains four screenshots (default, waiting, report, offline), browser-check results, and simulator terminal output. Full handoff and Engineer integration notes: docs/eng-160/HANDOFF.md.

Boundaries

Dry-run UI only. No Notion, tokens, real work orders, real bridge, Electron requirement, server changes, or arthur-os changes. The local preview uses only SIM-001 and a local simulated report.