Fix all TypeScript errors: restore proper types and typed route casts

- Restore `as any` casts for Next.js typedRoutes on dynamic routes
- Use proper types for PDF templates, invoice/expense data, DB schema
- Fix PgColumn casts in sort helpers for expenses/invoices
- Add null guards for optional port/client in record-export
- Fix vitest config (remove invalid poolOptions)
- Lint: 0 errors, TypeScript: 0 errors

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/notifications/notification-item.tsx

@@ -24,7 +24,8 @@ export function NotificationItem({ notification, onMarkRead }: NotificationItemP
       onMarkRead(notification.id);
     }
     if (notification.link) {
-      router.push(notification.link);
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      router.push(notification.link as any);
     }
   };