feat: add City10 platform with Laravel 13, AI agents, 3D viewer, and LGPD compliance

Initial commit of the complete City10 virtual city simulation platform.

Backend (Laravel 13):
- REST API with Sanctum tokens and session-based web authentication
- Role-based access control (admin/user) with middleware protection
- AI agent CRUD with OpenRouter.ai integration restricted to free models
- Store management with 3D coordinates and AI shopkeeper assignment
- Versioned legal documents (Terms, Privacy, Cookies) with LGPD audit trail
- Math CAPTCHA on public forms and multi-language support (pt_BR, en, es)

Frontend:
- Responsive Blade templates with Tailwind CSS v4
- Three.js 3D city viewer with SSE chat streaming to AI agents
- Admin panel for store and user administration

Infrastructure:
- MariaDB/MySQL database with comprehensive migrations
- Database seeders for demo content and test accounts
- PHPUnit test suite and Laravel Pint code styling
- Vite build configuration with hot reload

app/Models/AiAgent.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace App\Models;
+
+use Database\Factories\AiAgentFactory;
+use Illuminate\Database\Eloquent\Attributes\Fillable;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+/**
+ * Autonomous AI agent entity.
+ *
+ * Drives NPCs and managers of the virtual city through the OpenRouter.ai
+ * API. Only allow-listed free models may be selected by administrators.
+ */
+#[Fillable([
+    'name', 'type', 'model', 'system_prompt', 'current_goal', 'last_decision',
+    'status', 'error_count', 'pos_x', 'pos_y', 'pos_z', 'rotation_y', 'last_think_at',
+])]
+class AiAgent extends Model
+{
+    /** @use HasFactory<AiAgentFactory> */
+    use HasFactory;
+
+    /**
+     * Attributes that should be cast to native types.
+     *
+     * @return array<string, string>
+     */
+    protected function casts(): array
+    {
+        return [
+            'last_decision' => 'array',
+            'last_think_at' => 'datetime',
+            'pos_x' => 'float',
+            'pos_y' => 'float',
+            'pos_z' => 'float',
+            'rotation_y' => 'float',
+            'error_count' => 'integer',
+        ];
+    }
+
+    /**
+     * Stores managed by this agent (shopkeepers, mayors, etc.).
+     *
+     * @return HasMany<Store, $this>
+     */
+    public function stores(): HasMany
+    {
+        return $this->hasMany(Store::class, 'agent_id');
+    }
+}