Per PRIMING.md principle "Redundant Monitoring Is Resilience", add convoy
completion checks to Witness and Refinery for redundant observation:
- New internal/convoy/observer.go with shared CheckConvoysForIssue function
- Witness: checks convoys after successful polecat nuke in HandleMerged
- Refinery: checks convoys after closing source issue in both success handlers
Multiple observers closing the same convoy is idempotent - each checks if
convoy is already closed before running `gt convoy check`.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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