5ab7ff0f84
- Added 12 table-driven test cases covering all validation scenarios - Added 2 rollback tests (validation error + DB conflict) - Added nil item detection to prevent panic - Fixed nil pointer panic in CreateIssues - Tests verify ID uniqueness, timestamps, closed_at invariant - All tests pass Amp-Thread-ID: https://ampcode.com/threads/T-61c584cd-d873-4a1a-bfa6-d739b630b3e5 Co-authored-by: Amp <amp@ampcode.com>