User: Write a React counter component

Agent: I'll create a counter component and add logs to verify the functionality works properly.
[Start dev-log service, generate sessionId: sess_8x7k2p]

```jsx
function Counter() {
  const [count, setCount] = useState(0);
  const increment = () => {
    fetch('http://localhost:54321',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({sessionId:'sess_8x7k2p',time:new Date().toTimeString().split(' ')[0],type:'before-increment',data:{count}})}).catch(()=>{});
    setCount(c => c + 1);
  };
  return <button onClick={increment}>Count: {count}</button>;
}

### Example 2: Track Asynchronous Requests

```markdown
User: This async function sometimes fails, help me check it

Agent: [uses dev-log skill] Starting log service...

```javascript
async function fetchData(userId) {
  fetch('http://localhost:54321',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({sessionId:'sess_a1b2c3',time:new Date().toTimeString().split(' ')[0],type:'fetch-start',data:{userId}})}).catch(()=>{});

  try {
    const response = await fetch(`/api/users/${userId}`);
    fetch('http://localhost:54321',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({sessionId:'sess_a1b2c3',time:new Date().toTimeString().split(' ')[0],type:'fetch-response',data:{status:response.status,ok:response.ok}})}).catch(()=>{});

    if (!response.ok) {
      fetch('http://localhost:54321',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({sessionId:'sess_a1b2c3',time:new Date().toTimeString().split(' ')[0],type:'fetch-error',data:{status:response.status}})}).catch(()=>{});
      throw new Error(`HTTP ${response.status}`);
    }

    const data = await response.json();
    fetch('http://localhost:54321',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({sessionId:'sess_a1b2c3',time:new Date().toTimeString().split(' ')[0],type:'fetch-success',data:{hasData:!!data}})}).catch(()=>{});

    return data;
  } catch (error) {
    fetch('http://localhost:54321',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({sessionId:'sess_a1b2c3',time:new Date().toTimeString().split(' ')[0],type:'catch-error',data:{message:error.message}})}).catch(()=>{});
    throw error;
  }
}

### Example 3: Form Validation Tracking

```markdown
User: Write validation logic for a login form

Agent: [Start dev-log, generate sessionId: sess_valid9]

```javascript
function validateLoginForm(form) {
  const email = form.email.value;
  const password = form.password.value;

  fetch('http://localhost:54321',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({sessionId:'sess_valid9',time:new Date().toTimeString().split(' ')[0],type:'validate-input',data:{field:'email',value:email}})}).catch(()=>{});

  const errors = {};

  if (!email) {
    errors.email = '邮箱不能为空';
  }

  fetch('http://localhost:54321',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({sessionId:'sess_valid9',time:new Date().toTimeString().split(' ')[0],type:'validate-result',data:{field:'email',valid:!!email}})}).catch(()=>{});

  // ... More validation

  fetch('http://localhost:54321',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({sessionId:'sess_valid9',time:new Date().toTimeString().split(' ')[0],type:'final-result',data:{errorCount:Object.keys(errors).length}})}).catch(()=>{});

  return { valid: Object.keys(errors).length === 0, errors };
}

## Implementation

### Service Startup

**Startup Command:**
```bash
cd skills/dev-log && ./start.sh

./skills/dev-log/
├── start.sh         # Startup script (check/start service)
├── read-log.sh      # Log reading script (supports filtering)
├── server.js        # HTTP server (ESM module)
├── pid.txt          # Service process ID
├── port.txt         # Service port
└── dev-logs.json    # Log file (JSON format)

./skills/dev-log/read-log.sh

./skills/dev-log/read-log.sh "$SESSION_ID"

fetch('http://localhost:PORT',{
  method:'POST',
  headers:{'Content-Type':'application/json'},
  body:JSON.stringify({
    sessionId:'SESSION_ID',
    time:'TIME',
    type:'TYPE',
    data:DATA
  })
}).catch(()=>{})

fetch('http://localhost:PORT',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({sessionId:'SID',time:'TIME',type:'TYPE',data:DATA})}).catch(()=>{})