transform admin panel with comprehensive professional UI

- migrate from SQLite to PostgreSQL with Drizzle ORM
- implement comprehensive AdminLayout with expandable sidebar navigation
- create professional dashboard with real-time charts and metrics
- add advanced monitoring, reporting, and export functionality
- fix menu alignment and remove non-existent pages
- eliminate duplicate headers and improve UI consistency
- add Tailwind CSS v3 for professional styling
- expand database schema from 6 to 15 tables
- implement role-based access control and API key management
- create comprehensive settings, monitoring, and system info pages

styles/globals.css

@@ -0,0 +1,43 @@
+@tailwind base;
+@tailwind components;
+@tailwind utilities;
+
+@layer base {
+  html {
+    font-family: 'Inter', system-ui, sans-serif;
+  }
+  
+  body {
+    @apply bg-gray-50 text-gray-900;
+  }
+}
+
+@layer components {
+  .card {
+    @apply bg-white rounded-lg shadow-sm border border-gray-200;
+  }
+  
+  .btn-primary {
+    @apply bg-primary-600 hover:bg-primary-700 text-white font-medium px-4 py-2 rounded-md transition-colors duration-200 flex items-center justify-center;
+  }
+  
+  .btn-secondary {
+    @apply bg-white hover:bg-gray-50 text-gray-900 font-medium px-4 py-2 rounded-md border border-gray-300 transition-colors duration-200 flex items-center justify-center;
+  }
+  
+  .btn-danger {
+    @apply bg-red-600 hover:bg-red-700 text-white font-medium px-4 py-2 rounded-md transition-colors duration-200 flex items-center justify-center;
+  }
+  
+  .input {
+    @apply block w-full rounded-md border-gray-300 shadow-sm focus:border-primary-500 focus:ring-primary-500 sm:text-sm;
+  }
+  
+  .stat-card {
+    @apply card p-6 transition-all duration-200 hover:shadow-md;
+  }
+  
+  .table-row {
+    @apply border-b border-gray-200 hover:bg-gray-50 transition-colors duration-150;
+  }
+}