feat(expose): prefer live tap previews

[TraderSamwise]

Summary

• prefer live pane tap snapshots when serializing Exposé preview data
• keep capture snapshots as fallback/repair for tap misses only
• expand switchable-agent response coverage for tap-over-capture, capture fallback, and tap-only previews

Verification

• yarn vitest run src/metadata-server.test.ts src/tmux/expose-model.test.ts src/tmux/expose.test.ts
• yarn typecheck
• yarn lint
• yarn build
• yarn test
• pre-push hook: yarn typecheck && yarn lint && yarn test

Summary by CodeRabbit

• Bug Fixes
  • Improved preview snapshots for switchable windows.
  • Previews now prioritize the latest available pane output, with cached snapshots used as a fallback.
  • Ensured previews are correctly displayed across multiple windows, including windows with tap-only or cached preview data.
• Tests
  • Expanded coverage for multiple preview sources and window configurations.

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Project	Deployment	Actions	Updated (UTC)
app	Ready	Preview, Comment	Jul 21, 2026 3:07am

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: b9415652-abf6-46e8-90b2-37b9ef68c497

📥 Commits

Reviewing files that changed from the base of the PR and between 7bd5876 and c06f0e0.

📒 Files selected for processing (2)

• src/metadata-server.test.ts
• src/metadata-server.ts

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📝 Walkthrough

Walkthrough

The switchable-agents route now reads live pane previews first, falls back to cached previews when needed, and attaches the selected snapshot to each response item. Tests cover distinct preview sources across windows @7, @8, and @9.

Changes

Switchable-agent preview resolution

Layer / File(s)	Summary
Tap-first preview resolution src/metadata-server.ts	The includePreview flow reads pane tap snapshots for all items, queries the preview cache only for tap misses, and prefers tap snapshots when building responses.
Multi-window preview validation src/metadata-server.test.ts	Test fixtures and assertions cover cached, live-tap, and tap-only previews across windows @7, @8, and @9, including updated call expectations.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• TraderSamwise/aimux#371: Introduces the pane output tap integration used by this preview flow.
• TraderSamwise/aimux#368: Adds the previewSnapshot contract propagated by this route.
• TraderSamwise/aimux#369: Updates the same route’s cache-based preview attachment behavior.

Suggested reviewers: bhanuprasad14

Sequence Diagram(s)

sequenceDiagram
  participant SwitchableAgents as PROJECT_API_ROUTES.controls.switchableAgents
  participant ExposePaneOutputTap
  participant ExposePreviewCache
  SwitchableAgents->>ExposePaneOutputTap: Read previews for `@7`, `@8`, and `@9`
  SwitchableAgents->>ExposePreviewCache: Get previews only for tap misses
  SwitchableAgents-->>SwitchableAgents: Prefer tap snapshot, otherwise cache snapshot
  SwitchableAgents-->>SwitchableAgents: Attach previewSnapshot to each item

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🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: preferring live pane tap previews over cached capture snapshots.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/expose-live-tap-snapshots

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