fix(search): preserve connector failure diagnostics

[waleedlatif1]

Summary

• Preserve the known Calendar account-status reason and distinguish PostgreSQL statement timeouts, lock timeouts, cancellations, and other recognized abort causes in structured diagnostics.
• Record the operation and elapsed time when the connector tombstone check fails. Keep existing queries, retries, account isolation, and error propagation unchanged.
• These changes improve diagnosis; they do not claim to resolve the underlying provider access failures or database performance issues. Unknown messages, SQL parameters, and document content remain excluded from the new diagnostic fields.

Type of Change

• Bug fix

Testing

• 358 targeted tests passed across Google error handling, per-account scheduling, connector sync, document processing, workspace file dispatch, and shared error utilities.
• Regression coverage verifies private-data exclusion, bounded cause traversal, preserved error propagation, and continued processing after an account-specific failure.
• App type-check, lint, all 46 repository audits (including API validation), block registry validation, and docs manifest check passed. Committed artifact generators are in sync.

Checklist

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

[vercel]

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Project	Deployment	Actions	Updated
docs	Ready	Preview	Sep 18, 2026 3:04am UTC

[cubic-dev-ai]

No issues found across 12 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

The PR appears safe to merge; the diagnostic additions are bounded, preserve existing control flow, and have focused regression coverage.

Summary

This PR improves connector failure diagnostics without changing retry or propagation behavior.

• Preserves the allowlisted Google Calendar notACalendarUser reason.
• Classifies recognized PostgreSQL cancellation and abort causes using bounded cause traversal and fixed diagnostic values.
• Adds operation and elapsed-time context when the connector tombstone query fails.
• Adds regression coverage for sanitization, propagation, scheduling, and failure handling.

_{Reviews (1) · Last reviewed commit: "fix(search): preserve connector failure ..."}