feat(FN-4978): merge fusion/fn-4978

.changeset/fn-4978-empty-placeholder-title-normalization.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": patch
+---
+
+Normalize task titles by stripping empty placeholder bracket groups (`()`, `[]`, `{}`) left by FN-token removal and AI-generated blank template slots.

AGENTS.md

@@ -176,7 +176,7 @@ Detailed mechanism logs live in `docs/architecture.md` and `docs/design/`. The c
 - **Restart recovery**: `RestartRecoveryCoordinator` classifies interrupted `in-progress` runs. Unusable-worktree session-start failures (`missing`, `incomplete`, `unregistered git worktree`) are recoverable; retries are capped at `MAX_WORKTREE_SESSION_RETRIES=3` before escalating.
 - **Executor pre-session liveness gate (FN-4935)**: the gate now skips for fresh acquisitions (`acquisition.source === "fresh"`), emits structured `not_usable_task_worktree:<classification>` diagnostics (including canonicalized registered-path snapshots) and a `worktree:incomplete-detected` audit event with `source: "executor-liveness-gate"`, while preserving the existing `taskDoneRetryCount` / `MAX_TASK_DONE_REQUEUE_RETRIES` requeue contract. FN-4651 `worktreeSessionRetryCount` remains scoped to the in-review/session-start recovery path.
 - **Stale self-owned active-session reconcile on conflict cleanup (FN-4973)**: when executor worktree-conflict cleanup finds only a same-task stale `activeSessionRegistry` entry and no live in-memory `activeWorktrees` binding for that task/path, it must unregister the stale entry before `removeWorktree` (plus one-shot backstop reconcile on same-task `ActiveSessionWorktreeRemovalError` races). Foreign-task entries remain protected by FN-4811 and must never be reconciled by the requesting task.
-- **Task title/ID drift (FN-4898)**: active and archived title writes normalize foreign embedded `FN-NNN` tokens via `packages/core/src/task-title-id-drift.ts`. Lineage is preserved in `sourceParentTaskId` / description markers, not title embeds.
+- **Task title/ID drift (FN-4898)**: active and archived title writes normalize foreign embedded `FN-NNN` tokens via `packages/core/src/task-title-id-drift.ts`. Empty placeholder groups (`()`, `[]`, `{}`) left behind by token stripping are also removed in both `normalizeTitleForTaskId` and `sanitizeTitle` (FN-4978). Lineage is preserved in `sourceParentTaskId` / description markers, not title embeds.
 - **PR-conflict reclaim wiring (FN-4763)**: GitHub PR refresh now persists normalized `prInfo.mergeable` conflict state and, when conflicting, funnels tasks into self-healing’s existing reclaim machinery (`reclaimPrConflictForTask` / `reclaim-pr-conflicts` stage) so branch-conflict handling stays centralized with existing `inspectBranchConflict` outcomes and unrecoverable pause semantics.
 - **Worktrunk-managed lifecycles**: when `worktrunk.enabled`, self-healing defers prune/idle/worktree-cap sweeps to the worktrunk backend; branch-level reclaim and orphan rescue stay native.
 - **Post-finalize verification no-op (FN-4944)**: when auto-merge receives a delayed `VerificationError` after a task is already `done` with `mergeDetails.mergeConfirmed === true` (already-on-main fast-path), it must log one `[verification] ... no action` diagnostic and must not bounce the task back to `in-progress` / `merging-fix`. Defense-in-depth now re-checks the done+mergeConfirmed condition immediately before each verification-failure status write site, and emits `task:post-finalize-verification-no-op` database audit events with failure metadata for forensics.

packages/core/src/__tests__/ai-summarize.test.ts

@@ -305,6 +305,13 @@ describe("ai-summarize", () => {
       expect(sanitizeTitle("Why?")).toBe("Why");
     });
 
+    it("strips empty placeholder groups (FN-4978 regression)", () => {
+      expect(sanitizeTitle("Fix executor.ts stale session deadlock ( )")).toBe("Fix executor.ts stale session deadlock");
+      expect(sanitizeTitle("Add feature []")).toBe("Add feature");
+      expect(sanitizeTitle("Refactor (hotfix)")).toBe("Refactor (hotfix)");
+      expect(sanitizeTitle("( )")).toBeNull();
+    });
+
     it("hard-caps at MAX_TITLE_LENGTH", () => {
       const long = "x".repeat(100);
       const out = sanitizeTitle(long)!;

packages/core/src/__tests__/task-title-id-drift.test.ts

@@ -48,9 +48,36 @@ describe("task-title-id-drift", () => {
     expect(normalizeTitleForTaskId("Foo FN-100:", "FN-999")).toEqual({ title: "Foo", changed: true });
   });
 
+  it("strips empty placeholder left by fn-token removal (FN-4978 regression)", () => {
+    const normalized = normalizeTitleForTaskId("Fix executor.ts stale session deadlock (FN-1234)", "FN-9999");
+    expect(normalized).toEqual({ title: "Fix executor.ts stale session deadlock", changed: true });
+    expect(normalized.title).not.toContain("(");
+    expect(normalized.title).not.toContain(")");
+  });
+
+  it("strips empty square and curly bracket placeholders", () => {
+    expect(normalizeTitleForTaskId("Bug [FN-1] thing", "FN-9")).toEqual({ title: "Bug thing", changed: true });
+    expect(normalizeTitleForTaskId("Bug {FN-1} thing", "FN-9")).toEqual({ title: "Bug thing", changed: true });
+  });
+
+  it("preserves valid qualifiers and matching row id token", () => {
+    expect(normalizeTitleForTaskId("Refactor parser (hotfix)", "FN-9")).toEqual({
+      title: "Refactor parser (hotfix)",
+      changed: false,
+    });
+    expect(normalizeTitleForTaskId("Add docs (FN-9)", "FN-9")).toEqual({
+      title: "Add docs (FN-9)",
+      changed: false,
+    });
+  });
+
   it("is idempotent", () => {
     const first = normalizeTitleForTaskId("Refinement: FN-100: foo", "FN-200");
     const second = normalizeTitleForTaskId(first.title ?? "", "FN-200");
     expect(second.changed).toBe(false);
+
+    const firstPlaceholderPass = normalizeTitleForTaskId("Fix executor.ts stale session deadlock (FN-1234)", "FN-9999");
+    const secondPlaceholderPass = normalizeTitleForTaskId(firstPlaceholderPass.title ?? "", "FN-9999");
+    expect(secondPlaceholderPass.changed).toBe(false);
   });
 });

packages/core/src/ai-summarize.ts

@@ -12,6 +12,7 @@
  */
 
 import { getFnAgent, type AgentMessage } from "./ai-engine-loader.js";
+import { stripEmptyPlaceholders } from "./task-title-id-drift.js";
 
 // ── Constants ───────────────────────────────────────────────────────────────
 
@@ -880,6 +881,8 @@ export function sanitizeTitle(raw: string | undefined | null): string | null {
     return null;
   }
 
+  title = stripEmptyPlaceholders(title);
+
   // Drop trailing punctuation that summary-like sentences leave behind.
   title = title.replace(/[.!?,;:]+$/, "").trim();
   if (!title) return null;

packages/core/src/task-title-id-drift.ts

@@ -3,6 +3,31 @@ import { MAX_TITLE_LENGTH } from "./ai-summarize.js";
 export const TASK_ID_TOKEN_RE = /\bFN-(\d+)\b/gi;
 
 const CONNECTOR_RE = /[:\-—–]/;
+const EMPTY_PLACEHOLDER_CONTENT_RE = /^[\s,:;\-—–.!?]*$/;
+
+export function stripEmptyPlaceholders(text: string): string {
+  let normalized = text;
+
+  // Remove empty bracketed placeholders ((), [], {}) that contain only
+  // whitespace or punctuation residue/connectors.
+  normalized = normalized.replace(/\(([^)]*)\)|\[([^\]]*)\]|\{([^}]*)\}/g, (match, paren, square, brace) => {
+    const content = (paren ?? square ?? brace ?? "").trim();
+    return EMPTY_PLACEHOLDER_CONTENT_RE.test(content) ? " " : match;
+  });
+
+  normalized = normalized
+    .replace(/\s+([,:;.!?])/g, "$1")
+    .replace(/([:\-—–])\s*(?=[:\-—–])/g, "$1")
+    .replace(/\s+/g, " ")
+    .trim();
+
+  normalized = normalized
+    .replace(new RegExp(`(?:\\s*${CONNECTOR_RE.source}\\s*)+$`), "")
+    .replace(/[,:;.!?]+$/g, "")
+    .trim();
+
+  return normalized;
+}
 
 export function extractTaskIdTokens(title: string): string[] {
   const tokens = new Set<string>();
@@ -36,15 +61,7 @@ export function normalizeTitleForTaskId(
   }
 
   let normalized = initial.replace(/\bFN-\d+\b\s*([:\-—–])?\s*/gi, " ");
-  normalized = normalized
+  normalized = stripEmptyPlaceholders(normalized);
-    .replace(/\s+([,:;.!?])/g, "$1")
-    .replace(/\s+/g, " ")
-    .trim();
-
-  normalized = normalized
-    .replace(new RegExp(`(?:\\s*${CONNECTOR_RE.source}\\s*)+$`), "")
-    .replace(/[,:;.!?]+$/g, "")
-    .trim();
 
   if (normalized.length > MAX_TITLE_LENGTH) {
     normalized = normalized.slice(0, MAX_TITLE_LENGTH).trim();