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/Http/Requests/RegisterRequest.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace App\Http\Requests;
+
+use App\Http\Requests\Traits\ValidatesMathCaptcha;
+use Illuminate\Contracts\Validation\ValidationRule;
+use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Validation\Rule;
+use Illuminate\Validation\Rules\Password;
+use Illuminate\Validation\Validator;
+
+/**
+ * Validates new account registrations submitted through the public form.
+ */
+class RegisterRequest extends FormRequest
+{
+    use ValidatesMathCaptcha;
+
+    /**
+     * Determine if the user is authorized to make this request.
+     */
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    /**
+     * Get the validation rules that apply to the request.
+     *
+     * @return array<string, ValidationRule|array<mixed>|string>
+     */
+    public function rules(): array
+    {
+        return [
+            'name' => ['required', 'string', 'max:120'],
+            'email' => ['required', 'string', 'email', 'max:255', Rule::unique('users', 'email')],
+            'password' => ['required', 'confirmed', Password::min(8)],
+            'locale' => ['nullable', Rule::in(['pt_BR', 'en', 'es'])],
+            'captcha' => ['required', 'integer'],
+        ];
+    }
+
+    /**
+     * Configure the validator instance.
+     *
+     * @param  Validator  $validator
+     */
+    public function withValidator($validator): void
+    {
+        $validator->after(function ($validator): void {
+            if (! $this->validateMathCaptcha()) {
+                $validator->errors()->add('captcha', __('validation.captcha_failed'));
+            }
+        });
+    }
+}