feat(city): add plaza exercise system with health tracking

- 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

app/Models/Character.php

@@ -17,8 +17,8 @@ use Illuminate\Database\Eloquent\Relations\HasMany;
  */
 #[Fillable([
     'user_id', 'city_id', 'name', 'skin', 'hair', 'shirt',
-    'pos_x', 'pos_y', 'pos_z', 'money', 'energy', 'hunger', 'thirst',
-    'state', 'job_id', 'house_id', 'education', 'is_online', 'last_tick_at',
+    'pos_x', 'pos_y', 'pos_z', 'money', 'energy', 'hunger', 'thirst', 'health',
+    'state', 'job_id', 'house_id', 'education', 'exercise_count', 'is_online', 'last_tick_at',
     'hospitalized_until',
 ])]
 class Character extends Model
@@ -34,6 +34,13 @@ class Character extends Model
 
     public const STATE_STUDYING = 'studying';
 
+    /**
+     * Character is exercising on public plaza gym equipment.
+     *
+     * @var string
+     */
+    public const STATE_EXERCISING = 'exercising';
+
     /**
      * Character admitted to the hospital after a traffic accident.
      *
@@ -42,11 +49,14 @@ class Character extends Model
     public const STATE_HOSPITAL = 'hospital';
 
     /**
-     * Hospital stay length in seconds (two game days of 240s each).
+     * Hospital stay length in seconds (one game hour).
+     *
+     * The day/night cycle is 240 real seconds per 24 game hours, so one
+     * game hour equals 10 real seconds.
      *
      * @var int
      */
-    public const HOSPITAL_STAY_SECONDS = 480;
+    public const HOSPITAL_STAY_SECONDS = 10;
 
     /**
      * Default hospital bed coordinates used when no hospital building exists.
@@ -153,8 +163,10 @@ class Character extends Model
             'energy' => 100,
             'hunger' => 100,
             'thirst' => 100,
+            'health' => 100,
             'state' => self::STATE_AWAKE,
             'education' => 0,
+            'exercise_count' => 0,
             'is_online' => false,
         ]);
 
@@ -189,7 +201,9 @@ class Character extends Model
             'energy' => 'integer',
             'hunger' => 'integer',
             'thirst' => 'integer',
+            'health' => 'integer',
             'education' => 'integer',
+            'exercise_count' => 'integer',
             'is_online' => 'boolean',
             'last_tick_at' => 'datetime',
             'hospitalized_until' => 'datetime',
@@ -207,7 +221,7 @@ class Character extends Model
     }
 
     /**
-     * Admit the character to the hospital for two game days after an accident.
+     * Admit the character to the hospital for one game hour after an accident.
      *
      * Teleports them to the city hospital bed and returns the bed position.
      *
@@ -236,7 +250,7 @@ class Character extends Model
     }
 
     /**
-     * Release the character from the hospital when the stay has elapsed.
+     * Release the character from the hospital when the one-hour stay has elapsed.
      */
     public function releaseIfHospitalStayOver(): bool
     {