feat: implement comprehensive email system with rate limiting and extensive test suite

- Add robust email service with rate limiting and configuration management
- Implement shared rate limiter utility for consistent API protection
- Create comprehensive test suite for core processing pipeline
- Add API tests for dashboard metrics and authentication routes
- Fix date range picker infinite loop issue
- Improve session lookup in refresh sessions API
- Refactor session API routing with better code organization
- Update processing pipeline status monitoring
- Clean up leftover files and improve code formatting

components/theme-provider.tsx

@@ -15,4 +15,4 @@ interface ThemeProviderProps {
 
 export function ThemeProvider({ children, ...props }: ThemeProviderProps) {
   return <NextThemesProvider {...props}>{children}</NextThemesProvider>;
-}
+}