Add complete Laravel LLM Gateway implementation

Core Features:
- Multi-provider support (OpenAI, Anthropic, DeepSeek, Gemini, Mistral)
- Provider service architecture with abstract base class
- Dynamic model discovery from provider APIs
- Encrypted per-user provider credentials storage

Admin Interface:
- Complete admin panel with Livewire components
- User management with CRUD operations
- API key management with testing capabilities
- Budget system with limits and reset schedules
- Usage logs with filtering and CSV export
- Model pricing management with cost calculator
- Dashboard with Chart.js visualizations

Database Schema:
- MariaDB migrations for all tables
- User provider credentials (encrypted)
- LLM request logging
- Budget tracking and rate limiting
- Model pricing configuration

API Implementation:
- OpenAI-compatible endpoints
- Budget checking middleware
- Rate limit enforcement
- Request logging jobs
- Cost calculation service

Testing:
- Unit tests for all provider services
- Provider factory tests
- Cost calculator tests

Documentation:
- Admin user seeder
- Model pricing seeder
- Configuration files

laravel-app/app/Services/LLM/Providers/MistralProvider.php

@@ -0,0 +1,90 @@
+<?php
+
+namespace App\Services\LLM\Providers;
+
+use App\Models\ModelPricing;
+use Illuminate\Support\Facades\Cache;
+
+class MistralProvider extends AbstractProvider
+{
+    protected string $baseUrl = 'https://api.mistral.ai/v1';
+
+    protected function buildRequest(array $messages, array $options): array
+    {
+        return array_filter([
+            'model' => $options['model'] ?? 'mistral-small-latest',
+            'messages' => $messages,
+            'temperature' => $options['temperature'] ?? 0.7,
+            'max_tokens' => $options['max_tokens'] ?? null,
+            'top_p' => $options['top_p'] ?? null,
+            'stream' => false,
+            'safe_prompt' => $options['safe_prompt'] ?? false,
+            'random_seed' => $options['random_seed'] ?? null,
+        ], fn($value) => $value !== null && $value !== false);
+    }
+
+    protected function getAuthHeaders(): array
+    {
+        return [
+            'Authorization' => 'Bearer ' . $this->apiKey,
+            'Content-Type' => 'application/json',
+        ];
+    }
+
+    public function chatCompletion(array $messages, array $options = []): array
+    {
+        $data = $this->buildRequest($messages, $options);
+        return $this->makeRequest('/chat/completions', $data);
+    }
+
+    public function normalizeResponse(array $response): array
+    {
+        return [
+            'id' => $response['id'] ?? null,
+            'model' => $response['model'] ?? null,
+            'content' => $response['choices'][0]['message']['content'] ?? '',
+            'role' => $response['choices'][0]['message']['role'] ?? 'assistant',
+            'finish_reason' => $response['choices'][0]['finish_reason'] ?? null,
+            'usage' => [
+                'prompt_tokens' => $response['usage']['prompt_tokens'] ?? 0,
+                'completion_tokens' => $response['usage']['completion_tokens'] ?? 0,
+                'total_tokens' => $response['usage']['total_tokens'] ?? 0,
+            ],
+            'raw_response' => $response,
+        ];
+    }
+
+    public function calculateCost(int $promptTokens, int $completionTokens, string $model): float
+    {
+        $cacheKey = "pricing:mistral:{$model}";
+
+        $pricing = Cache::remember($cacheKey, 3600, function () use ($model) {
+            return ModelPricing::where('provider', 'mistral')
+                ->where('model', $model)
+                ->where('is_active', true)
+                ->first();
+        });
+
+        if (!$pricing) {
+            return 0.0;
+        }
+
+        $promptCost = ($promptTokens / 1_000_000) * $pricing->input_price_per_million;
+        $completionCost = ($completionTokens / 1_000_000) * $pricing->output_price_per_million;
+
+        return round($promptCost + $completionCost, 6);
+    }
+
+    public function getSupportedModels(): array
+    {
+        return [
+            'mistral-large-latest',
+            'mistral-medium-latest',
+            'mistral-small-latest',
+            'mistral-tiny',
+            'open-mistral-7b',
+            'open-mixtral-8x7b',
+            'open-mixtral-8x22b',
+        ];
+    }
+}