feat(FN-3867): add changeset for paused scope exclusion feature

Completes Step 4 by adding a patch changeset for `@runfusion/fusion`, signaling that the FN-3864 scope-exclusion work is ready for the next release.

Fusion-Task-Id: FN-3867

.changeset/fn-3864-paused-scope-exclusion.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": patch
+---
+
+Scheduler: exclude paused in-review tasks from `activeScopes`. Paused failed-merge tasks no longer block dispatch of overlapping todo tasks via `blockedBy` re-stamping. (FN-3867)

packages/engine/src/__tests__/scheduler.test.ts

@@ -793,6 +793,80 @@ describe("Scheduler", () => {
       expect(updateTask).not.toHaveBeenCalledWith("FN-002", { status: "queued", blockedBy: "FN-001" });
     });
 
+    it("excludes paused in-review tasks from active scopes", async () => {
+      vi.mocked(existsSync).mockReturnValue(true);
+      vi.mocked(readFile).mockResolvedValue("# Task\nDo something");
+
+      const tasks = [
+        createMockTask({ id: "FN-001", column: "in-review", paused: true, worktree: "/test/project/.worktrees/fn-001" }),
+        createMockTask({ id: "FN-002", column: "todo" }),
+      ];
+
+      const parseScopeMock = vi.fn(async (taskId: string): Promise<string[]> => {
+        if (taskId === "FN-001") return ["src/foo.ts"];
+        if (taskId === "FN-002") return ["src/foo.ts"];
+        return [];
+      });
+
+      const updateTask = vi.fn().mockResolvedValue(undefined);
+      const moveTask = vi.fn().mockResolvedValue(undefined);
+      const store = createMockStore({
+        listTasks: vi.fn().mockResolvedValue(tasks),
+        getSettings: vi.fn().mockResolvedValue({
+          maxConcurrent: 2,
+          maxWorktrees: 4,
+          groupOverlappingFiles: true,
+        }),
+        parseFileScopeFromPrompt: parseScopeMock,
+        updateTask,
+        moveTask,
+      });
+
+      const scheduler = new Scheduler(store);
+      (scheduler as any).running = true;
+      await scheduler.schedule();
+
+      expect(moveTask).toHaveBeenCalledWith("FN-002", "in-progress", expect.objectContaining({ allocateWorktree: expect.any(Function) }));
+      expect(updateTask).not.toHaveBeenCalledWith("FN-002", { status: "queued", blockedBy: "FN-001" });
+    });
+
+    it("blocks todo when overlapping in-review task is not paused", async () => {
+      vi.mocked(existsSync).mockReturnValue(true);
+      vi.mocked(readFile).mockResolvedValue("# Task\nDo something");
+
+      const tasks = [
+        createMockTask({ id: "FN-001", column: "in-review", worktree: "/test/project/.worktrees/fn-001" }),
+        createMockTask({ id: "FN-002", column: "todo" }),
+      ];
+
+      const parseScopeMock = vi.fn(async (taskId: string): Promise<string[]> => {
+        if (taskId === "FN-001") return ["src/foo.ts"];
+        if (taskId === "FN-002") return ["src/foo.ts"];
+        return [];
+      });
+
+      const updateTask = vi.fn().mockResolvedValue(undefined);
+      const moveTask = vi.fn().mockResolvedValue(undefined);
+      const store = createMockStore({
+        listTasks: vi.fn().mockResolvedValue(tasks),
+        getSettings: vi.fn().mockResolvedValue({
+          maxConcurrent: 2,
+          maxWorktrees: 4,
+          groupOverlappingFiles: true,
+        }),
+        parseFileScopeFromPrompt: parseScopeMock,
+        updateTask,
+        moveTask,
+      });
+
+      const scheduler = new Scheduler(store);
+      (scheduler as any).running = true;
+      await scheduler.schedule();
+
+      expect(updateTask).toHaveBeenCalledWith("FN-002", { status: "queued", blockedBy: "FN-001" });
+      expect(moveTask).not.toHaveBeenCalledWith("FN-002", "in-progress");
+    });
+
     it("still blocks overlap for non-ignored paths", async () => {
       vi.mocked(existsSync).mockReturnValue(true);
       vi.mocked(readFile).mockResolvedValue("# Task\nDo something");

packages/engine/src/scheduler.ts

@@ -661,9 +661,12 @@ export class Scheduler {
           const filteredScope = filterPathsByIgnoreList(scope, overlapIgnorePaths);
           if (filteredScope.length > 0) activeScopes.set(t.id, filteredScope);
         }
-        // In-review tasks with unmerged worktrees
+        // Paused in-review tasks (e.g., failed-merge tasks awaiting human triage) cannot
+        // make progress, so they must not contribute to activeScopes. Including them
+        // caused a deadlock pattern where a paused task indefinitely re-stamped
+        // `blockedBy` on overlapping todo tasks every scheduler tick. (FN-3867 / FN-3857)
         const inReviewWithWorktree = tasks.filter(
-          (t) => t.column === "in-review" && t.worktree,
+          (t) => t.column === "in-review" && t.worktree && !t.paused,
         );
         for (const t of inReviewWithWorktree) {
           const scope = await this.store.parseFileScopeFromPrompt(t.id);