feat(FN-4068): add branch conflict detection and recovery for stale worktre

Implements branch conflict detection and recovery across the Fusion engine, CLI, and dashboard — surfacing git worktree conflicts when tasks conflict with unrelated branch state, and providing a recovery workflow to resolve them. The executor and worktree pool now integrate typed branch conflict che

Fusion-Task-Id: FN-4068

packages/cli/src/plugins/__tests__/bundled-plugin-install.test.ts

@@ -593,5 +593,5 @@ describe("ensureBundledDependencyGraphPluginInstalled", () => {
       await rm(stagedRoot, { recursive: true, force: true });
       await rm(pluginStateRoot, { recursive: true, force: true });
     }
-  });
+  }, 20_000);
 });