fix: surface reviewer response failures

backend/test/session-bridge.test.ts

@@ -105,6 +105,30 @@ test("assistant provider errors are sanitized and leave the turn failed", () =>
   expect(JSON.stringify(seen)).not.toContain("DO_NOT_LEAK");
 });
 
+test("subscription model errors become a safe actionable client message", () => {
+  const { rpc, fire } = fakeRpc();
+  const bridge = new SessionBridge(rpc);
+  const seen: any[] = [];
+  bridge.onClientEvent((event) => seen.push(event));
+
+  fire({
+    type: "message_end",
+    message: {
+      role: "assistant",
+      stopReason: "error",
+      errorMessage: "429: {\"code\":\"1311\",\"message\":\"Your current subscription plan does not yet include access to GLM-5.3\",\"secret\":\"DO_NOT_LEAK\"}",
+    },
+  });
+
+  expect(seen).toContainEqual({
+    type: "info",
+    level: "error",
+    text: "The selected model is unavailable for the current subscription. Choose another model and start a new session.",
+  });
+  expect(JSON.stringify(seen)).not.toContain("GLM-5.3");
+  expect(JSON.stringify(seen)).not.toContain("DO_NOT_LEAK");
+});
+
 test("markFailed records backend-detected failure without emitting raw detail", () => {
   const { rpc } = fakeRpc();
   const bridge = new SessionBridge(rpc);