huskies: merge 913

server/src/pipeline_state/transition.rs

@@ -181,6 +181,12 @@ pub fn transition(state: Stage, event: PipelineEvent) -> Result<Stage, Transitio
         // ── MergeFailed: Merge → MergeFailure (recoverable intermediate) ──
         (Merge { .. }, MergeFailed { reason }) => Ok(MergeFailure { reason }),
 
+        // ── MergeFailure self-loop: repeated failure is a no-op ─────────────
+        // When the mergemaster retries and fails again while the story is already
+        // in MergeFailure, treat it as a silent self-transition so callers can
+        // detect the no-op via `fired.before == MergeFailure` and skip re-notifying.
+        (MergeFailure { .. }, MergeFailed { reason }) => Ok(MergeFailure { reason }),
+
         (Merge { .. }, MergeFailedFinal { reason }) => Ok(Archived {
             archived_at: now,
             reason: ArchiveReason::MergeFailed { reason },