Verify the counter app works at {{URL}}.

## Steps

1. Open {{URL}} with agent-browser
2. Take a snapshot to find the counter display and increment button
3. Note the initial count value
4. Click the increment button
5. Wait briefly for the state to update
6. Take a new snapshot and check the count increased

## Pass criteria

- The page loads without errors
- There is a visible count display
- There is a clickable increment button
- After clicking +, the count increases by 1
