feat: add ToastProvider and PDFPreview component

- Integrated ToastProvider into the Providers component for global toast notifications.
- Added PDFPreview component for displaying PDF files with a modal interface.
- Updated UI package index to export new components.
- Implemented toast functionality with customizable types and auto-dismiss feature.

Author: Harshvardhan-91

apps/web/app/dashboard/page.tsx

@@ -39,3 +39,31 @@ body {
 html, body {
   overflow-x: hidden;
 }
+
+/* Custom animations for the landing page */
+@keyframes spin-slow {
+  from {
+    transform: rotate(0deg);
+  }
+  to {
+    transform: rotate(360deg);
+  }
+}
+
+.animate-spin-slow {
+  animation: spin-slow 20s linear infinite;
+}
+
+@keyframes gradient-shift {
+  0%, 100% {
+    background-position: 0% 50%;
+  }
+  50% {
+    background-position: 100% 50%;
+  }
+}
+
+.animate-gradient {
+  background-size: 200% 200%;
+  animation: gradient-shift 3s ease infinite;
+}