fix(search): preserve Gmail reads when replies disappear

[waleedlatif1]

Summary

• Preserve the requested Gmail message and readable replies when an optional reply disappears after thread discovery, and mark conversation coverage incomplete.
• Handle only the missing reply's 404; retain authorization checks and propagate credential, quota, server, and cancellation failures.

Type of Change

• Bug fix

Testing

• Google content HTTP acceptance: 54 checks passed; missing-reply cases fail before each fix for both metadata verification and full-message reads. Synthetic loopback fixtures exercise the production reader and transport, not a connected Google account.
• Three independent mutation controls reject a broad error catch, missing coverage warning, and stopping before remaining readable replies.
• Live-provider regression suite: 240 tests passed across 30 files.
• App type-check, lint, 51 audits, block registry check, artifact generators, and docs manifest check passed.

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing (new tests pass the test-audit authoring gate)
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

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1 Skipped Deployment

Project	Deployment	Actions	Updated
docs	Skipped		Sep 28, 2026 9:03pm UTC

[waleedlatif1]

@greptile

[waleedlatif1]

@cubic-dev-ai review this PR

[cubic-dev-ai]

@cubic-dev-ai review this PR

@waleedlatif1 I have started the AI code review. It will take a few minutes to complete.

[cubic-dev-ai]

No issues found across 2 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

_{Re-trigger cubic}

[greptile-apps]

Confidence Score: 5/5

[Medium risk] Adds error handling to Gmail message fetch.

The PR appears safe to merge; the previously reported verification-time missing-reply failure is fixed.

Summary

The PR preserves a requested Gmail message and readable replies when another reply disappears, marking conversation coverage incomplete. The follow-up change also handles a 404 during per-reply verification and adds HTTP regression cases for metadata and full-message failures.

_{Reviews (2) · Last reviewed commit: "fix(search): handle replies missing duri..."}

[waleedlatif1]

@greptile

[waleedlatif1]

@cubic-dev-ai review this PR

[cubic-dev-ai]

@cubic-dev-ai review this PR

@waleedlatif1 I have started the AI code review. It will take a few minutes to complete.

[cubic-dev-ai]

No issues found across 2 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

_{Re-trigger cubic}