fix(desktop): clear consistent advisory smoke baseline failures

[oscarlehuu]

Problem

Advisory Desktop Smoke on main had a consistent fail set across the two most recent completed CI runs used as baseline:

• run 31567957800 (#155 middle-page scroll)
• run 31563476933 (exact local snapshot focus refresh)

Target families (intersection, not one-run flakes):

Spec	Symptom
evidence-reactions.spec.ts:46	strict-mode: evidence-reaction-rejected resolves 2 nodes after Reject
channels.spec.ts:1951	message-timeline-day-group count 0 after bulk live emit
channels.spec.ts:2108	agent session panel stays on skeleton; never "No ACP activity yet"
channel-activity-popover.spec.ts (multiple)	popover under-counts activity / mark-read starves

No GitHub issue — intentional baseline cleanup PR.

Approach (per-spec)

Spec	Root cause	Kind	Fix
evidence-reactions Reject	Reject calls onReply → thread panel mounts same message as head; dual card is product-correct	harness	Scope card locator to message-timeline
channels sticky day divider	Live emit of 2023 timestamps is outside live backlog grace and never lands in the window; even recent post-open backdates hit grace	harness	Seed two recent local days into the mock store before open (emitLive: false) so head window loads them with hasMore:false → both virtualized day dividers prove
channels agent activity empty	getAgentObserverSnapshot maps open + no live contact → connecting even with zero events → infinite skeleton	product	Force connecting only when events.length > 0 without live contact (restored/replay path). Empty + open → idle open
channel-activity-popover	Unread live sub used bare since: now; self roots at now-20 dropped before onSelfChannelMessage → authoredRootIds never grows → bob replies fail notify gate	product	Same CHANNEL_LIVE_BACKLOG_GRACE_SECONDS as timeline buildChannelLiveFilter

Seams: useLiveChannelUpdates unread live filter; getAgentObserverSnapshot / observerRelayStore; smoke harness timestamps/selectors only.

Tests

Local (macOS, --project=smoke --retries=0 after pnpm --filter buzz build:e2e):

• evidence-reactions.spec.ts — 3 passed
• channels.spec.ts sticky day + agent activity — 2 passed
• channel-activity-popover.spec.ts — 10 passed
• observerPerAgentTelemetry.test.mjs — 10 passed (added empty+open idle case)
• pnpm typecheck, biome check on touched files

Acceptance on this PR: targeted smoke shards green. Integration lane drift is out of scope.

Docs

docs/crew/STATE.md — advisory smoke baseline cleanup note.

Risk

• Unread live grace replays up to 120s of member-channel events (same envelope as timeline live; merge is idempotent by id).
• Empty observer agents flip from permanent skeleton to empty idle copy — intended product behavior.

Exclusions

• Do not re-chase already-shipped baseline: channel-agent-presence (test(desktop): emit an authorizable 46040 in the channel presence spec #141), scroll-history (fix(desktop): restore fast middle-page scroll coverage setup (#155) #166/scroll-history.spec.ts:1281 — fast middle-page scroll settles with ~half the required mounted coverage #155), relay-reconnect (fix(desktop): keep interstitial older pages across reconnect freeze (#154) #167/relay-reconnect.spec.ts:617 — pre-disconnect message disappears from the timeline after a 260-message reconnect backfill #154).
• One-run flakes / hermes-profile / huddle-transcription / entity-link not expanded here.
• No e2eBridge.ts relay-mode handler edits (sibling feat(e2e): remaining bridge mutations relay-aware (Fixes #144) #168 lane).
• No assertion weakening, skips, or timeout inflation.