feat(FN-4001): merge fusion/fn-4001

Commits merged:
- merge fusion/fn-4001

Files changed:
packages/cli/src/__tests__/bundle-output.test.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Fusion-Task-Id: FN-4001

.changeset/FN-3846-phantom-merge-ancestor-shortcircuit.md

@@ -0,0 +1,10 @@
+---
+"@runfusion/fusion": patch
+---
+
+Fix phantom-merge guard stranding tasks whose branch content is already on
+main under a different SHA (sibling-task duplication, cherry-pick, prior
+in-merge fix). The merger finalize path now recognizes ancestor and
+equivalent-patch-id branches as a no-op success instead of refusing the
+merge. The FN-1858 phantom-merge guard remains intact for the real-phantom
+case (no recoverable content anywhere).