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/LegalDocument.php

@@ -0,0 +1,65 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Attributes\Fillable;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
+
+/**
+ * Versioned legal document (Terms of Use, Privacy Policy, Cookie Policy).
+ *
+ * Bodies are stored per language so that the UI can render the version
+ * matching the user's selected locale at acceptance time.
+ */
+#[Fillable(['type', 'version', 'title', 'body', 'is_current', 'published_at'])]
+class LegalDocument extends Model
+{
+    /**
+     * Document type: Terms of Use.
+     *
+     * @var string
+     */
+    public const TYPE_TERMS = 'terms';
+
+    /**
+     * Document type: Privacy Policy (LGPD).
+     *
+     * @var string
+     */
+    public const TYPE_PRIVACY = 'privacy';
+
+    /**
+     * Document type: Cookie Policy.
+     *
+     * @var string
+     */
+    public const TYPE_COOKIES = 'cookies';
+
+    /**
+     * Attributes that should be cast to native types.
+     *
+     * @return array<string, string>
+     */
+    protected function casts(): array
+    {
+        return [
+            'title' => 'array',
+            'body' => 'array',
+            'is_current' => 'boolean',
+            'published_at' => 'datetime',
+        ];
+    }
+
+    /**
+     * Users that accepted this document version.
+     *
+     * @return BelongsToMany<User, $this>
+     */
+    public function users(): BelongsToMany
+    {
+        return $this->belongsToMany(User::class, 'user_consents')
+            ->withPivot(['accepted_at', 'ip_address', 'user_agent', 'source'])
+            ->withTimestamps();
+    }
+}