Mobile: show chat titles instead of raw stream paths

Status summary: done — PR #2490, CI fully green (preview e2e included), zero review threads. Server exposes agent titles through itx.agents.list(), the mobile chat list renders them and stays LIVE off the agent catalog's push channel, the thread header folds the title from the event stream. Along the way this exposed and fixed a pre-existing platform flaw: subscribing to agents.liveState on a fresh project (zero chats) errored and stayed dead.

Prompted by a screenshot of the mobile chat list showing rows like mobile/2026-08-12t23-27-59-114z — the raw agent stream path — where a human-readable title should be. Agents already set a title on their first turn (agent/summary-updated, per AGENT_SUMMARY_INSTRUCTION), and the web sidebar shows it; mobile just had no way to read it: itx.agents.list() returned only path + createdAt.

Checklist#

• Expose title from itx.agents.list() new AgentListItem type in apps/os/src/domains/agents/agent-presence.ts; list() in rpc-targets.ts maps summary.title through; regenerated the itx API projections with pnpm generate:itx-api
• Chat list rows render the title apps/mobile/.../index.tsx: title in normal weight, mono path fallback for chats whose agent has not set one yet
• Chat list goes LIVE useLiveState((itx) => itx.agents.liveState) takes over after the list() first paint — titles pop in on push, and chats started on web/Slack appear without navigation refetches (the spec exposed that returning from a chat showed a stale list)
• Thread header renders the title apps/mobile/.../chat.tsx: folded from the already-loaded event stream via new latestAgentTitle in lib/chat.ts (same set/clear/preserve semantics as threadContextForScriptRun); raw path stays reachable via the ••• menu
• Platform fix: agents.liveState on a fresh project subscribing before the first agent create() was refused with stream-subscription-unconfigured and the watcher stayed dead (latent in the dashboard sidebar too); AgentCollectionLiveStateRpcTarget in rpc-targets.ts now appends the idempotency-keyed birth batch on exactly that refusal and retries once
• Tests latestAgentTitle unit cases in apps/mobile/src/lib/chat.test.ts; RN-web spec specs/mobile/chat-titles.spec.ts (signup → new chat → path fallback → /script appends the summary fact with ZERO model turns → title takes over header and list); e2e live-state.e2e.test.ts "subscribed before any agent exists" guards the platform fix; specs/mobile/notifications.spec.ts heading assertion updated for the now-titled header

Decisions / assumptions#

• Fixed the product surface rather than having mobile dig into reduced state ad hoc: title is public catalog data, every list() consumer benefits, and the live list rides the same useLiveState primitive the dashboard sidebar uses.
• title is optional on the wire — absent until the agent's first turn lands — so clients keep a path fallback.
• The platform fix is birth-on-refusal (not birth-on-every-subscribe): the already-born common path pays nothing; only the fresh-project refusal triggers the idempotent birth batch append + one retry.

Implementation log#

• agents.list() e2e assertions (itx-agents.e2e.test.ts) use objectContaining/empty-list — tolerant of the added field, no changes needed.
• The chat-titles spec failed twice before going green: first on the stale list after goBack (fixed by the live list), then on the fresh-project liveState refusal (fixed by the platform change). Verified the push mechanics with a throwaway node script before wiring the UI.
• CI's preview lane failed on notifications.spec.ts waiting for a heading named elsewhere-thread — that spec seeds a summary title, so the header now (correctly) shows the title instead; assertion updated.
• Root-worktree typecheck noise encountered along the way, none of it from this change: stale expo route typegen + missing expo-media-library in apps/mobile, *ignoreme* scratch files in apps/os.