chore: carry the RPC-02 deadline-race test fix and re-pin the template

The synced suite contained an assertion that pinned one of two equally
configured deadlines, so it passed alone and failed in a full parallel
run. Fixed upstream and carried here with the template pin moved to
`a0fbafb`.

Three consecutive runs of the 27-file set that reproduced the failure now
pass at 485 tests.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/unit/browser-rpc/browser-rpc-remediation.test.ts

@@ -645,10 +645,17 @@ describe("RPC-01 only a positive receipt confirms physical closure", () => {
     );
 
     expect(results).toHaveLength(1);
-    expect(results[0]).toMatchObject({
-      ok: false,
-      error: { code: "RPC_TOTAL_DEADLINE_EXCEEDED" },
-    });
+    // The subject is that a throwing accessor cannot replace the outcome the
+    // runtime already selected, not which deadline won. `totalDeadlineMs` and
+    // `idleDeadlineMs` are deliberately equal here, so pinning one of the two
+    // timeout codes would make this assertion a coin flip under load.
+    expect(results[0]).toMatchObject({ ok: false });
+    const failure = results[0] as { error: { kind: string; code: string } };
+    expect(failure.error.kind).toBe("REQUEST_TIMEOUT");
+    expect([
+      "RPC_TOTAL_DEADLINE_EXCEEDED",
+      "RPC_STREAM_IDLE_TIMEOUT",
+    ]).toContain(failure.error.code);
     expect(cancels).toHaveLength(1);
   });