[Astro-Han]

Summary

• wait for the optimistic user message before exercising slash commands during the first running turn
• use active-session transcript ownership as the readiness signal instead of treating the Stop button as a proxy
• prevent /side discovery from racing the first send's asynchronous setActiveId

Verification

• npx biome check apps/desktop/e2e/slash-command-menu.spec.ts
• npm --workspace @maka/desktop run build:with-deps
• focused regression repeated 5 times: 5 passed
• slash-command-menu.spec.ts: 4 passed

Root cause

The test continued as soon as the locally armed turn exposed the Stop button. The first-send path sets the active session only after sessions.send resolves, while /side is cataloged only when an active session exists. The test could therefore open the slash menu before the session-owning transcript was ready and wait forever on an option that was omitted from that menu instance.

Checklist

• Tests cover the change and fail without it
• Lint, format, typecheck and the affected suites pass locally

Does this PR entail a change in behavior?

• Yes — described under Summary above
• No

[Astro-Han]

All checks are green. This just fixes a race in the E2E setup and doesn’t change product behavior, so I’m merging it as a low-risk test-only change.