- Adds CityPlazas support class for deterministic public plaza generation with outdoor gym equipment
- Implements exercise and stop-exercise actions with proximity validation to equipment
- Introduces health (0-100) and exercise_count attributes to Character model
- Reduces hospital stay duration from two game days to one game hour
- Adds 3D gym equipment rendering (bench, bars, bike, treadmill) in city viewer
- Includes exercise state machine handling in world ticker with energy drain
- Adds comprehensive PlazaExerciseTest and updates HospitalAdmissionTest
- Provides localized UI strings for health HUD and exercise prompts