fix(models): retry timeout errors by default

src/models/retry.test.ts

@@ -8,9 +8,9 @@ describe('isRetryable', () => {
     expect(isRetryable(error, DEFAULT_RETRY_CONFIG.nonRetryablePatterns)).toBe(true);
   });
 
-  it('returns false for timeout errors', () => {
+  it('returns true for timeout errors (transient)', () => {
     const error = new Error('Request timed out after 20000ms');
-    expect(isRetryable(error, DEFAULT_RETRY_CONFIG.nonRetryablePatterns)).toBe(false);
+    expect(isRetryable(error, DEFAULT_RETRY_CONFIG.nonRetryablePatterns)).toBe(true);
   });
 
   it('returns false for authentication errors', () => {