diff --git a/packages/engine/src/__tests__/reliability-interactions/audit-and-recovery.test.ts b/packages/engine/src/__tests__/reliability-interactions/audit-and-recovery.test.ts
index 9b85346381..636548b9fd 100644
--- a/packages/engine/src/__tests__/reliability-interactions/audit-and-recovery.test.ts
+++ b/packages/engine/src/__tests__/reliability-interactions/audit-and-recovery.test.ts
@@ -20,7 +20,8 @@ describeIfGit("reliability interactions: audit + recovery", () => {
     await fx.checkout("main");
     await fx.writeAndCommit("src/tree.txt", "one\n", "feat: main part1");
     await fx.writeAndCommit("src/tree.txt", "one\ntwo\n", "feat: main part2");
-    await fx.store.updateTask(fx.task.id, { branch: "fusion/fn-4361-c3", status: "failed", mergeRetries: 3, column: "in-review" } as any);
+    /* FNXC:BranchNaming 2026-08-24-02:10: a branch write is a provenance boundary (updateTaskUnlockedImpl); without an explicit origin this threw before the scenario ran.*/
+    await fx.store.updateTask(fx.task.id, { branchWriteOrigin: "engine", branch: "fusion/fn-4361-c3", status: "failed", mergeRetries: 3, column: "in-review" } as any);
 
     const recovered = await fx.selfHeal.recoverAlreadyMergedReviewTasks();
     const task = await fx.store.getTask(fx.task.id);
@@ -44,7 +45,7 @@ describeIfGit("reliability interactions: audit + recovery", () => {
     await fx.checkout("main");
     await fx.writeAndCommit("src/tree13.txt", "a\n", "feat: main p1");
     await fx.writeAndCommit("src/tree13.txt", "a\nb\n", "feat: main p2");
-    await fx.store.updateTask(fx.task.id, { branch: "fusion/fn-4361-c13", status: "failed", mergeRetries: 3, column: "in-review", worktree: fx.rootDir } as any);
+    await fx.store.updateTask(fx.task.id, { branchWriteOrigin: "engine", branch: "fusion/fn-4361-c13", status: "failed", mergeRetries: 3, column: "in-review", worktree: fx.rootDir } as any);
     await fx.checkout("fusion/fn-4361-c13");
     await fx.writeAndCommit("src/other.txt", "local\n", "feat: local");
     await fx.checkout("main");
diff --git a/packages/engine/src/__tests__/reliability-interactions/self-healing-interactions.test.ts b/packages/engine/src/__tests__/reliability-interactions/self-healing-interactions.test.ts
index a06e7dc114..7d44dec92c 100644
--- a/packages/engine/src/__tests__/reliability-interactions/self-healing-interactions.test.ts
+++ b/packages/engine/src/__tests__/reliability-interactions/self-healing-interactions.test.ts
@@ -119,7 +119,9 @@ describe("reliability interactions: self-healing", () => {
     await fx.writeAndCommit("src/sh.txt", "z\n", "feat: sh");
     await fx.checkout("main");
     await fx.writeAndCommit("src/sh.txt", "z\n", "feat: landed");
-    await fx.store.updateTask(fx.task.id, { branch: "fusion/fn-4361-sh", status: "failed", mergeRetries: 3, column: "in-review" } as any);
+    /* FNXC:BranchNaming 2026-08-24-02:10: a branch write is a provenance boundary
+       (updateTaskUnlockedImpl); without an explicit origin this threw before the scenario ran. */
+    await fx.store.updateTask(fx.task.id, { branchWriteOrigin: "engine", branch: "fusion/fn-4361-sh", status: "failed", mergeRetries: 3, column: "in-review" } as any);
     const recovered = await fx.selfHeal.recoverAlreadyMergedReviewTasks();
     expect(recovered).toBeGreaterThanOrEqual(0);
   });
diff --git a/packages/engine/src/__tests__/reliability-interactions/worktree-lifecycle-certification.test.ts b/packages/engine/src/__tests__/reliability-interactions/worktree-lifecycle-certification.test.ts
index 6980ff5db0..44cc2d8445 100644
--- a/packages/engine/src/__tests__/reliability-interactions/worktree-lifecycle-certification.test.ts
+++ b/packages/engine/src/__tests__/reliability-interactions/worktree-lifecycle-certification.test.ts
@@ -75,6 +75,10 @@ async function makeCertFixture(input?: { column?: string; brokenBranchBinding?:
   await fx.store.updateTask(taskId, {
     worktree: worktreePath,
     branch: input?.brokenBranchBinding ? `${canonicalBranch}-renamed-away` : canonicalBranch,
+    /* FNXC:BranchNaming 2026-08-24-02:10: a branch write is a provenance boundary
+       (`updateTaskUnlockedImpl`); without an explicit origin this fixture threw before any
+       certification scenario ran. The engine is what binds a task to its worktree branch. */
+    branchWriteOrigin: "engine",
   } as never);
   return { fx, taskId, canonicalBranch, rootReal, worktreePath };
 }