784. Traffic Light

Build a traffic light that cycles continuously through three vehicle signals using fixed durations.

Requirements

1. Signal cycle

• Start on green.
• Repeat forever: green → yellow → red → green.

2. Timing (use these exact values)

3. Rendering

• Always render three lamps (red, yellow, green).
• Exactly one is active at a time; the active one must be obvious.

4. Timers & lifecycle

• Use one scheduled timeout per step (avoid overlapping setInterval loops).
• Clear pending timeouts on cleanup so unmount and re-renders do not leak or double-schedule.

Time target: ~25–35 minutes.