test: cover tools error mapping and unify timeout fallback check

sdk/src/gsd-transport.ts

@@ -1,7 +1,7 @@
 import type { QueryResult } from './query/utils.js';
 import type { QueryRegistry } from './query/registry.js';
 import type { TransportMode } from './gsd-transport-policy.js';
-import { isTimeoutLikeError } from './query-failure-classification.js';
+import { toFailureSignal } from './query-failure-classification.js';
 
 export interface TransportRequest {
   legacyCommand: string;
@@ -49,7 +49,7 @@ export class GSDTransport {
         // Do not subprocess-fallback after a timed-out native dispatch:
         // the timeout does not cancel the native handler, so falling through
         // would run the same command twice (double-execution race).
-        if (isTimeoutLikeError(error)) throw error;
+        if (toFailureSignal(error).kind === 'timeout') throw error;
       }
     }
 

sdk/src/query-tools-error-mapper.test.ts

@@ -0,0 +1,21 @@
+import { describe, expect, it } from 'vitest';
+import { ErrorClassification, GSDError } from './errors.js';
+import { toGSDToolsError } from './query-tools-error-mapper.js';
+
+describe('query tools error mapper', () => {
+  it('maps GSDError to GSDToolsError exit code', () => {
+    const err = toGSDToolsError('state', ['load'], new GSDError('bad input', ErrorClassification.Validation));
+    expect(err.exitCode).toBe(10);
+    expect(err.message).toBe('bad input');
+  });
+
+  it('attaches timeout classification when message indicates timeout', () => {
+    const err = toGSDToolsError('state', ['load'], new Error('gsd-tools timed out after 1234ms: state load'));
+    expect(err.classification).toEqual({ kind: 'timeout', timeoutMs: 1234 });
+  });
+
+  it('does not attach timeout classification for non-timeout failures', () => {
+    const err = toGSDToolsError('state', ['load'], new Error('boom'));
+    expect(err.classification).toBeUndefined();
+  });
+});