fix(server): threads settle as soon as a client sees their PR merge

[t3dotgg]

A PR merged on GitHub showed "Merged" in the thread details panel right away, but the sidebar badge stayed open and the thread did not settle for up to a minute.

The two views read different sources. The panel reads the PR detail from the host. The sidebar and settlement read the snapshot on the thread's PR link, which only the sync reactor writes, on a 1-minute sweep. The detail read already knew the new state, but nothing told the reactor.

Now a detail read that sees a PR for the first time, or in a new state, announces it. The sync reactor listens and syncs that link at once, so the badge updates and the thread settles as soon as any client (or a PR watch) sees the merge. Only detail reads announce, ordered by updatedAt and then observedAt, and merged stays final, so stale cached reads cannot flip a link back. The 1-minute sweep stays as the fallback.

Cost: at most one extra summary read per state change a reader sees.

Reviewed by GPT-6.1 Sol over 3 rounds (plan, code, follow-up).

Created with Claude Opus 5.5 in Claude Code.

🤖 Generated with Claude Code

[macroscopeapp]

Approvability

Verdict: Approved at 16f6678

Macroscope's review found this PR approvable — This is a small, targeted synchronization bug fix that connects fresh pull-request detail observations to the existing thread snapshot and settlement path. Its bounded state tracking and event-driven refresh are covered by focused tests, with the periodic sweep retained as a fallback.

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[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

ℹ️ The exact PR base did not have a successful artifact. Baseline uses the latest successful main measurement shown below.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	4.9 KiB	5.0 KiB	+23 B (+0.5%)	6.8 KiB	✅
Codex	Thread snapshot wire	3.8 KiB	3.8 KiB	0 B (0.0%)	4.9 KiB	✅
Codex	Live turn WebSocket wire	1.2 KiB	1.2 KiB	+23 B (+1.9%)	2.0 KiB	✅
Codex	Live turn WebSocket decoded	20.8 KiB	20.9 KiB	+41 B (+0.2%)	29.3 KiB	✅
Codex	Live turn messages	1	2	+1 (+100.0%)	8	✅
Claude	Total thread wire	5.0 KiB	5.0 KiB	−41 B (−0.8%)	6.8 KiB	✅
Claude	Thread snapshot wire	3.8 KiB	3.8 KiB	0 B (0.0%)	4.9 KiB	✅
Claude	Live turn WebSocket wire	1.2 KiB	1.2 KiB	−41 B (−3.3%)	2.0 KiB	✅
Claude	Live turn WebSocket decoded	21.2 KiB	21.2 KiB	−41 B (−0.2%)	29.3 KiB	✅
Claude	Live turn messages	2	1	−1 (−50.0%)	8	✅

Baseline: 250e052 · PR result: 16f6678 · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 108.5 KiB
• Claude decoded thread snapshot: 108.8 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Path: .coderabbit.config.ts
• Review profile: CHILL
• Plan: Team
• Run ID: 3ec6e626-59b7-4a32-bbce-a6bdc55fe7b9

📥 Commits

Reviewing files that changed from the base of the PR and between 655dfbe and 16f6678.

📒 Files selected for processing (4)

• apps/server/src/orchestration-v2/PullRequestSyncReactor.test.ts
• apps/server/src/orchestration-v2/PullRequestSyncReactor.ts
• apps/server/src/pullRequest/PullRequestService.test.ts
• apps/server/src/pullRequest/PullRequestService.ts

Included review availability: This review used your included allowance. Your plan provides up to 10 included reviews per hour; 2 remain after this review.

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📝 Walkthrough

Walkthrough

Detail reads now publish accepted pull-request state changes. The sync reactor consumes these notifications and requests a sync without waiting for the next scheduled sweep.

Changes

Pull request state-change sync

Layer / File(s)	Summary
Track and publish detail-read state changes apps/server/src/pullRequest/PullRequestService.ts, apps/server/src/pullRequest/PullRequestService.test.ts	The service compares detail readings by merge state, updatedAt, and observedAt. It publishes a key when an accepted detail reading changes state. Tests cover initial and changed states, repeated readings, and stale readings.
Request syncs from state-change notifications apps/server/src/orchestration-v2/PullRequestSyncReactor.ts, apps/server/src/orchestration-v2/PullRequestSyncReactor.test.ts	The reactor consumes state-change notifications and requests a sync. The test verifies that a notification invalidates the pull-request reference and dispatches a sync without advancing the clock.

Priority: ⬇️ Low

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Bug fix

Sequence Diagram(s)

sequenceDiagram
  participant PullRequestService
  participant StateChangePubSub
  participant PullRequestSyncReactor
  PullRequestService->>StateChangePubSub: publish ThreadPullRequestKey
  StateChangePubSub->>PullRequestSyncReactor: emit state-change key
  PullRequestSyncReactor->>PullRequestSyncReactor: requestSync for the key

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Suggested reviewers: juliusmarminge

Merge Risk: ⚪ Minimal · up to 16f66

No actionable merge-blocking risk remains. Detail reads can request prompt syncs, and stale reads do not revert a held merge.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: threads settle sooner when a client sees that a pull request has merged.
Description check	✅ Passed	The description clearly explains the problem and the change. It does not include the required scope and approval information or verification results.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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