refactor: centralize query tools error construction in factory

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

@@ -0,0 +1,25 @@
+import { describe, expect, it } from 'vitest';
+import { ErrorClassification, GSDError } from './errors.js';
+import {
+  failureToolsError,
+  timeoutToolsError,
+  toToolsErrorFromUnknown,
+} from './query-tools-error-factory.js';
+
+describe('query tools error factory', () => {
+  it('builds timeout and failure tools errors', () => {
+    expect(timeoutToolsError('t', 'state', ['load'], '', 10).classification).toEqual({ kind: 'timeout', timeoutMs: 10 });
+    expect(failureToolsError('f', 'state', ['load'], 1).classification).toEqual({ kind: 'failure' });
+  });
+
+  it('maps GSDError to failure with semantic exit code', () => {
+    const err = toToolsErrorFromUnknown('state', ['load'], new GSDError('bad', ErrorClassification.Validation));
+    expect(err.exitCode).toBe(10);
+    expect(err.classification).toEqual({ kind: 'failure' });
+  });
+
+  it('maps timeout-like unknown errors to timeout classification', () => {
+    const err = toToolsErrorFromUnknown('state', ['load'], new Error('gsd-tools timed out after 50ms: state load'));
+    expect(err.classification).toEqual({ kind: 'timeout', timeoutMs: 50 });
+  });
+});