refactor: consolidate contact API logic and enhance error handling

- Migrate contact API from route.tsx to route.ts for improved organization.
- Implement filtering, pagination, and rate limiting for GET and POST requests.
- Enhance error handling for database operations, including graceful handling of missing tables.
- Validate input fields and email format in POST requests to ensure data integrity.

components/Toast.tsx

@@ -59,7 +59,7 @@ const ToastItem = ({ toast, onRemove }: ToastProps) => {
   const getColors = () => {
     switch (toast.type) {
       case 'success':
-        return 'bg-stone-50 border-green-200 text-green-800 shadow-md';
+        return 'bg-stone-50 border-green-300 text-green-900 shadow-md';
       case 'error':
         return 'bg-stone-50 border-red-200 text-red-800 shadow-md';
       case 'warning':
@@ -291,7 +291,7 @@ export const ToastProvider = ({ children }: { children: React.ReactNode }) => {
       {children}
       
       {/* Toast Container */}
-      <div className="fixed top-4 right-4 z-50 space-y-2 max-w-xs">
+      <div className="fixed top-4 right-4 z-50 space-y-3 max-w-sm">
         <AnimatePresence>
           {toasts.map((toast) => (
             <ToastItem