- Add a merger guard that verifies source fusion/FN branch attribution when rebase capture reports zero own commits
- Fail finalize with explicit no-op attribution mismatch handling instead of marking mergeConfirmed on ambiguous no-op ranges
- Type and emit dedicated audit events for mismatch and source-ref-unavailable skip diagnostics
- Expand branch attribution, merger, and reliability interaction tests to cover the full no-op guard matrix
Fusion-Task-Id: FN-5304
c5e9dc43f1