feat(world): add persistent citizen simulation with needs, jobs, and social features

- Adds Character model with survival needs (hunger, thirst, energy) and state machine
- Implements city:tick world ticker for offline progression every minute
- Adds city territory expansion and building construction system
- Introduces job economy, inventory, and transaction audit trail
- Adds social graph (friends, marriage, children) and character chat
- Implements admin approval workflow for new registrations
- Adds hospital admission system for traffic accidents
- Includes comprehensive feature tests and world seeders

app/Models/City.php

@@ -0,0 +1,113 @@
+<?php
+
+namespace App\Models;
+
+use Database\Factories\CityFactory;
+use Illuminate\Database\Eloquent\Attributes\Fillable;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+/**
+ * Geographic territory of a virtual city.
+ *
+ * Bounds drive street layout generation, movement clamping and construction
+ * limits. Administrators may expand bounds or create additional cities.
+ */
+#[Fillable([
+    'name', 'slug', 'bounds_min_x', 'bounds_max_x', 'bounds_min_z', 'bounds_max_z',
+    'is_active', 'expansions',
+])]
+class City extends Model
+{
+    /** @use HasFactory<CityFactory, $this> */
+    use HasFactory;
+
+    /**
+     * Maximum number of territory expansions allowed per city.
+     */
+    public const MAX_EXPANSIONS = 10;
+
+    /**
+     * Characters living in this city.
+     *
+     * @return HasMany<Character, $this>
+     */
+    public function characters(): HasMany
+    {
+        return $this->hasMany(Character::class);
+    }
+
+    /**
+     * Buildings placed inside this city.
+     *
+     * @return HasMany<Building, $this>
+     */
+    public function buildings(): HasMany
+    {
+        return $this->hasMany(Building::class);
+    }
+
+    /**
+     * Job positions offered in this city.
+     *
+     * @return HasMany<Job, $this>
+     */
+    public function jobs(): HasMany
+    {
+        return $this->hasMany(Job::class);
+    }
+
+    /**
+     * Find the active city used as the default world.
+     */
+    public static function active(): ?self
+    {
+        return self::query()->where('is_active', true)->orderBy('id')->first();
+    }
+
+    /**
+     * Expand territory eastward and northward by one grid step (40 units).
+     *
+     * Returns false when the expansion cap has been reached.
+     */
+    public function expand(): bool
+    {
+        if ($this->expansions >= self::MAX_EXPANSIONS) {
+            return false;
+        }
+
+        $this->bounds_max_x = (float) $this->bounds_max_x + 40;
+        $this->bounds_max_z = (float) $this->bounds_max_z + 40;
+        $this->expansions = (int) $this->expansions + 1;
+        $this->save();
+
+        return true;
+    }
+
+    /**
+     * Determine whether a world coordinate lies inside the city bounds.
+     */
+    public function contains(float $x, float $z): bool
+    {
+        return $x >= (float) $this->bounds_min_x && $x <= (float) $this->bounds_max_x
+            && $z >= (float) $this->bounds_min_z && $z <= (float) $this->bounds_max_z;
+    }
+
+    /**
+     * Get the attributes that should be cast.
+     *
+     * @return array<string, string>
+     */
+    protected function casts(): array
+    {
+        return [
+            'bounds_min_x' => 'float',
+            'bounds_max_x' => 'float',
+            'bounds_min_z' => 'float',
+            'bounds_max_z' => 'float',
+            'is_active' => 'boolean',
+            'expansions' => 'integer',
+        ];
+    }
+}