feat: multi-provider AI support with auto-detection

- Added support for Google Gemini, OpenAI, Anthropic, and Azure OpenAI
- Implemented API key validation with auto model detection
- Added Error Boundary for better error handling
- Migrated PDF generation to native jsPDF (better quality)
- Added PWA support with offline capabilities
- Implemented tests with Vitest
- Fixed language consistency (PT-BR)
- Improved accessibility (ARIA)

public/manifest.json

@@ -0,0 +1,22 @@
+{
+  "name": "SteelCheck - Análise de Qualidade Industrial",
+  "short_name": "SteelCheck",
+  "description": "Plataforma de análise de certificados de qualidade com IA",
+  "start_url": "/",
+  "display": "standalone",
+  "background_color": "#0f172a",
+  "theme_color": "#1e40af",
+  "orientation": "portrait-primary",
+  "icons": [
+    {
+      "src": "/icon-192.png",
+      "sizes": "192x192",
+      "type": "image/png"
+    },
+    {
+      "src": "/icon-512.png",
+      "sizes": "512x512",
+      "type": "image/png"
+    }
+  ]
+}

public/sw.js

@@ -0,0 +1,35 @@
+const CACHE_NAME = 'steelcheck-v1';
+const ASSETS = [
+  '/',
+  '/index.html',
+  '/index.tsx',
+  '/style.css'
+];
+
+self.addEventListener('install', (event) => {
+  event.waitUntil(
+    caches.open(CACHE_NAME).then((cache) => {
+      return cache.addAll(ASSETS);
+    })
+  );
+});
+
+self.addEventListener('fetch', (event) => {
+  event.respondWith(
+    caches.match(event.request).then((response) => {
+      return response || fetch(event.request);
+    })
+  );
+});
+
+self.addEventListener('activate', (event) => {
+  event.waitUntil(
+    caches.keys().then((cacheNames) => {
+      return Promise.all(
+        cacheNames
+          .filter((name) => name !== CACHE_NAME)
+          .map((name) => caches.delete(name))
+      );
+    })
+  );
+});