test: add stopReason edge case tests; update state.json with recent fixes

- Added tests for finish_reason 'tool_calls' with empty array → 'end_turn'
- Added test for finish_reason 'length' → 'max_tokens'
- Updated state.json with 4 new entries for today's fixes (SOUL.md, message
  normalization, agent loop resilience, stopReason normalization)
- Test count: 1329 → 1331

src/models/openai.test.ts

@@ -74,4 +74,50 @@ describe('OpenAIClient tool use', () => {
       args: { command: 'ls' },
     });
   });
+
+  it('maps finish_reason "tool_calls" with empty tool_calls to end_turn', async () => {
+    mockCreate.mockResolvedValueOnce({
+      choices: [{
+        message: {
+          content: 'I tried to call a tool but none matched.',
+          tool_calls: [],
+        },
+        finish_reason: 'tool_calls',
+      }],
+      usage: { prompt_tokens: 15, completion_tokens: 10 },
+    });
+
+    const client = new OpenAIClient({
+      apiKey: 'test-key',
+      model: 'gpt-4o',
+    });
+
+    const response = await client.chat({
+      messages: [{ role: 'user', content: 'do something' }],
+    });
+
+    expect(response.stopReason).toBe('end_turn');
+    expect(response.toolCalls).toBeUndefined();
+  });
+
+  it('maps finish_reason "length" to max_tokens', async () => {
+    mockCreate.mockResolvedValueOnce({
+      choices: [{
+        message: { content: 'Truncated output...' },
+        finish_reason: 'length',
+      }],
+      usage: { prompt_tokens: 100, completion_tokens: 4096 },
+    });
+
+    const client = new OpenAIClient({
+      apiKey: 'test-key',
+      model: 'gpt-4o',
+    });
+
+    const response = await client.chat({
+      messages: [{ role: 'user', content: 'write a long essay' }],
+    });
+
+    expect(response.stopReason).toBe('max_tokens');
+  });
 });