fix(web): prioritize linked pull requests over automatic diffs

[maria-rcks]

Linked pull requests could be missed while thread history loaded, and the multi-PR tab was not protected from automatic diffs. Open linked PRs from thread metadata immediately, using the existing PRs tab for multiple or foreign-repository links, and give them priority over completed-turn diffs.

Without a linked PR, only open a diff automatically for at least 3 changed files or 50 added/deleted lines. Preserve manual tab choices, the proactive-panels setting, and narrow-screen behavior.

Validation: 216 focused tests pass; web typecheck and scoped lint pass (existing warnings). Real-client checks confirmed single-PR opening before history finishes loading and immediate PRs-tab selection when a second real PR is linked. Read-only Codex turns preserved PR priority and later manual tab choices. At 390px, the sheet stayed closed automatically and opened manually from the PR badge. A single foreign link also selected the PRs tab with an independently discovered branch PR present.

Implemented with GPT-6 in Codex.

[macroscopeapp]

Approvability

Verdict: Approved at 936b397

Macroscope's review found this PR approvable — This is a focused fix to existing web panel prioritization and automatic diff thresholds, with targeted tests and no schema, security, infrastructure, or default-setting changes. The runtime impact is limited to selecting already-supported pull-request or diff panels while preserving manual choices.

^{You can add or adjust custom eligibility rules. Learn more.}

Dismissing prior approval to re-evaluate d2af9d6

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Advanced

Run ID: bc9aeedd-4ae0-4aab-a41e-55a73413bd82

📥 Commits

Reviewing files that changed from the base of the PR and between 32e8b25 and 936b397.

📒 Files selected for processing (6)

• apps/web/src/components/ChatView.logic.test.ts
• apps/web/src/components/ChatView.logic.ts
• apps/web/src/components/ChatView.tsx
• apps/web/src/components/settings/SettingsPanels.tsx
• apps/web/src/rightPanelStore.test.ts
• apps/web/src/rightPanelStore.ts

Included review availability: Your plan provides up to 10 included reviews per hour; 4 remain after this review.

---

📝 Walkthrough

Walkthrough

Changes

Proactive panel behavior

Layer / File(s)	Summary
Diff opening thresholds apps/web/src/components/ChatView.logic.ts, apps/web/src/components/ChatView.logic.test.ts, apps/web/src/components/settings/SettingsPanels.tsx	Completed-turn diffs now open only for at least 3 changed files or 50 changed lines. Tests cover threshold cases, and the setting description states these conditions.
Pull-request surface arbitration apps/web/src/rightPanelStore.ts, apps/web/src/rightPanelStore.test.ts	The right-panel store accepts the pull-request list surface and prevents proactive diffs from replacing either pull-request surface.
ChatView proactive routing apps/web/src/components/ChatView.tsx	ChatView selects between the linked pull-request and pull-request list surfaces using visible PR data, capability state, and linked detail availability. It also defers unresolved states and suppresses competing completion panels.

Priority: ⬇️ Low

Estimated code review effort: 3 (Moderate) | ~25 minutes

Change: Bug fix

Sequence Diagram(s)

sequenceDiagram
  participant ChatView
  participant RightPanelStore
  participant PullRequestsSurface
  participant DiffSurface
  ChatView->>RightPanelStore: evaluate visible pull requests and diff eligibility
  RightPanelStore->>PullRequestsSurface: open linked or list pull-request surface
  ChatView->>DiffSurface: open qualifying completed-turn diff

Loading

Suggested reviewers: t3dotgg

Merge Risk: ⚪ Minimal · up to 936b3

Foreign linked pull requests are routed to the pull-request list as intended. No actionable merge-blocking risk remains.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 4 functions across 6 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
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.
Title check	✅ Passed	The title clearly summarizes the primary change: prioritizing linked pull requests over automatic diffs.
Description check	✅ Passed	The description explains what changed, why it changed, affected UI behavior, validation results, and includes screenshots and a video. It does not use the template headings or include the checklist, b…

• Fix all pre-merge checks with AI

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

_{Comment @coderabbitai help to get the list of available commands.}