fix(session): preserve logical thread continuity

[marcusrbrown]

No description provided.

[fro-bot]

Summary

This PR correctly implements the fix for session title persistence identified in the post-ship audit. The root cause — OpenCode auto-renaming session titles after prompts — is addressed by re-asserting the title after each prompt attempt.

Key Changes

1. New title-reassert.ts module — Best-effort session title restoration

The implementation is well-designed:

• Null-safe early return when title is undefined
• Try/catch wrapper with warning-level logging (failures don't abort execution)
• Uses SDK's typed session.update endpoint

2. Integration in execution.ts — Correct placement in finally block

const result = await (async () => {
  try {
    return await sendPromptToSession(...)
  } finally {
    await reassertSessionTitle(client, sessionId, config?.sessionTitle, logger)
  }
})()

This ensures title re-assertion happens after every prompt attempt (including retries), which is the correct behavior.

3. Test coverage — Two new tests verify the behavior:

• 're-asserts session title with SDK update payload after prompt attempts'
• 're-asserts session title even when prompt attempt fails'

Both tests pass ✅.

Quality Assessment

✅ Tests pass — All 1068 tests pass including the new ones
✅ Type check clean — No TypeScript errors
✅ Lint clean — Only warnings in unrelated test files (pre-existing)
✅ Follows project patterns — Uses Logger injection, Result pattern would be overkill for best-effort operation
✅ Correct layering — New module in services/session/ where storage operations belong
✅ Documentation — Audit document clearly explains the fix

Minor Observations

1. as Record<string, unknown> cast — The type assertion on line 17 of title-reassert.ts is acceptable given the SDK's untyped endpoint, though a more precise type could be added if the SDK exposes the shape in the future.

2. Test mock coverage — The session.update mock is already present in createMockClient() at line 113 of the test file, which is good reuse of the test infrastructure.

Verdict

This is a targeted, correct fix for the identified root cause. The implementation is minimal, well-tested, and follows established patterns. The audit document provides excellent traceability from problem to fix.

Recommended action: Merge after CI passes.

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Run Summary

Field	Value
Event	pull_request
Repository	fro-bot/agent
Run ID	23686153603
Cache	hit
Session	ses_2cb6115dbffeuLRGFT6r9OoaMl