## Problem
CI integration test runs against the **live deployed gateway** (old image). The namespace validation test expects 400, but old image returns 404 → CI never promotes new image → chicken-and-egg.
## Fix
- Accept 400 or 404 for namespace test during rollout
- Add unit test confirming WorkflowAdapter returns 400 (passes locally)
- Add integration test for `POST /v1/webhooks/forgejo`
## Tests
- `go test ./internal/serviceadapter/... -run TestWorkflowListRequiresNamespace` passes locally
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Co-authored-by: Poimen <[email protected]>
Reviewed-on: #30
