refactor(desktop): classify preview exports

[juliusmarminge]

Preview and browser-import modules had ten unclassified runtime exports. This marks three canonical Effect service constructors as intentional public APIs, narrows six local implementation values, and removes one unused PreviewManager predicate while retaining exported schemas and types.

This is layer 4 of 5 in the desktop Knip cleanup stack.

Verification after the full stack: desktop typecheck; desktop Knip export audit; 831 desktop tests; changed-file lint and format checks. The native libsecret test cannot start on this machine because the system libsecret-1 development package is unavailable.

Model: gpt-6 astra. Harness: Codex in T3 Code.

Summary by CodeRabbit

• Documentation

  • Added documentation comments to public preview service constructors, improving API reference clarity.

• Refactor

  • Streamlined the preview module’s public API by keeping internal favicon, picture-in-picture, and error-handling helpers private.
  • No user-facing functionality or behavior was changed.

[macroscopeapp]

Approvability

Verdict: Approved at 97ae73e

Macroscope's review found this PR approvable — The PR only narrows internal preview module exports and documents retained Effect service constructors; helper implementations, constants, defaults, and runtime behavior remain unchanged. No product defaults or static-analysis suppressions are introduced, and no repository consumers of the removed exports were found.

No code changes detected at 3dc5b7c. Prior analysis still applies.

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[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

ℹ️ No successful main baseline artifact is available yet. This run establishes the initial measurement.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	—	13.6 KiB	—	15.1 KiB	✅
Codex	Thread snapshot wire	—	7.0 KiB	—	7.3 KiB	✅
Codex	Live turn WebSocket wire	—	6.5 KiB	—	7.8 KiB	✅
Codex	Live turn WebSocket decoded	—	57.1 KiB	—	66.4 KiB	✅
Codex	Live turn messages	—	10	—	21	✅
Claude	Total thread wire	—	13.5 KiB	—	15.1 KiB	✅
Claude	Thread snapshot wire	—	7.0 KiB	—	7.3 KiB	✅
Claude	Live turn WebSocket wire	—	6.5 KiB	—	7.8 KiB	✅
Claude	Live turn WebSocket decoded	—	57.8 KiB	—	66.4 KiB	✅
Claude	Live turn messages	—	8	—	21	✅

Baseline: unavailable · PR result: 3dc5b7c · 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: 113.9 KiB
• Claude decoded thread snapshot: 114.6 KiB

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

Dismissing prior approval to re-evaluate 97ae73e

[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: Team

Run ID: 87e721e3-104c-4d41-a00d-07d569484ba2

📥 Commits

Reviewing files that changed from the base of the PR and between 4c6bb9a and 3dc5b7c.

📒 Files selected for processing (4)

• apps/desktop/src/preview/BrowserImport/BrowserImport.ts
• apps/desktop/src/preview/BrowserSession.ts
• apps/desktop/src/preview/FaviconCapture.ts
• apps/desktop/src/preview/Manager.ts

Included review availability: 6 reviews are currently available. Your included PR review attempts over the past 7 days set your current allowance at 10 reviews per hour.

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📝 Walkthrough

Walkthrough

The preview modules now document canonical service constructors and restrict internal constants, data builders, and error type guards to module scope.

Changes

Preview API surface cleanup

Layer / File(s)	Summary
Document public service constructors apps/desktop/src/preview/BrowserImport/BrowserImport.ts, apps/desktop/src/preview/BrowserSession.ts, apps/desktop/src/preview/Manager.ts	Public API comments identify the make service constructors as part of the canonical Effect module API.
Restrict internal preview helpers apps/desktop/src/preview/FaviconCapture.ts, apps/desktop/src/preview/Manager.ts	The favicon URL limit, picture-in-picture data URL builder, and preview error type guards are no longer exported.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Merge Risk: ⚪ Minimal · up to 3dc5b

Desktop preview modules now clarify the public service constructors and keep internal helpers private without changing runtime behavior. No merge-blocking risk remains.

Suggested reviewers: chrisdeeming, stienswout

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 4…
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 identifies the main change: classifying preview exports in the desktop application.
Description check	✅ Passed	The description explains the export classification changes, the cleanup context, verification steps, and the unavailable libsecret test. It does not use the template headings or checklist, but it cont…

✨ 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 cleanup-desktop/preview-helpers

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