Added a cortisol gauge meter above the playing area:

- **Semicircular gauge** with colored segments (green → yellow → orange → red) matching the reference image
- **Animated needle** that smoothly moves toward the target level
- **Labels**: LOW, MEDIUM, HIGH and "CORTISOL" title
- **Bouncing at Goon, Sleep, Doomscrolling** → cortisol drops (needle moves left toward green/LOW)
- **Bouncing at Work, Home, School** → cortisol rises (needle moves right toward red/HIGH)
- Starts at 50% (medium) and resets on game restart

**Next Ideas:**
1. **Cortisol effects** - When cortisol is extremely high, add screen shake or red vignette; when low, add a calming glow effect
2. **Sound feedback** - Play a soothing chime when cortisol drops and an alarm buzz when it spikes high

**Ready to level up your game? Pick one and let's build it!**