Add Event Themes management page to dashboard

Introduced a new "Event Themes" page to allow users to manage visual themes for events. Updated the dashboard to include a button for navigating to the new page. The themes page supports listing, viewing, and creating themes, enhancing customization options for users.

frontend/src/app/(main)/dashboard/event-themes/page.tsx

@@ -0,0 +1,108 @@
+"use client";
+
+import { useQuery } from "@tanstack/react-query";
+import { listEventThemes } from "@/client/sdk.gen";
+import {
+  Card,
+  CardContent,
+  CardFooter,
+  CardHeader,
+  CardTitle,
+  CardDescription,
+} from "@/components/ui/card";
+import { Badge } from "@/components/ui/badge";
+import { Button } from "@/components/ui/button";
+import Image from "next/image";
+import Link from "next/link";
+import { Loader2Icon, PaletteIcon } from "lucide-react";
+import { useEventThemes } from "@/context/event-theme-context";
+
+export default function EventThemesPage() {
+  // const { data: themes, isLoading } = useQuery({
+  //     queryKey: ["event-themes"],
+  //     queryFn: () => listEventThemes().then(res => res.data),
+  // });
+
+  const { themes, isLoadingThemes } = useEventThemes();
+
+  return (
+    <div className="max-w-7xl mx-auto py-6 px-4">
+      <div className="flex items-center justify-between mb-8">
+        <div>
+          <h1 className="text-3xl font-bold">Event Themes</h1>
+          <p className="mt-2 text-gray-500 dark:text-gray-400">
+            Manage visual themes for your celebrations.
+          </p>
+        </div>
+        <Button asChild>
+          <Link href="/dashboard/event-themes/new">+ New Theme</Link>
+        </Button>
+      </div>
+
+      {isLoadingThemes && (
+        <div className="flex items-center gap-2">
+          <Loader2Icon className="animate-spin h-6 w-6 text-blue-500" />
+          <span>Loading themes...</span>
+        </div>
+      )}
+
+      {!isLoadingThemes && themes && themes.length === 0 && (
+        <div className="bg-gray-100 dark:bg-slate-700 rounded p-8 text-center">
+          <p className="text-gray-500 dark:text-gray-400">
+            You haven't created any theme yet.
+          </p>
+          <Button asChild className="mt-4">
+            <Link href="/dashboard/events/new">Create Your First Theme</Link>
+          </Button>
+        </div>
+      )}
+
+      {!isLoadingThemes && themes && themes.length > 0 && (
+        <div className="grid gap-6 sm:grid-cols-2 md:grid-cols-3 lg:grid-cols-4">
+          {themes.map((theme) => (
+            <Card
+              key={theme.id}
+              className="hover:shadow-lg transition-shadow flex flex-col overflow-hidden"
+            >
+              <CardHeader className="p-0 relative h-48 bg-gray-50 dark:bg-gray-800">
+                {theme.preview_image_url ? (
+                  <Image
+                    src={theme.preview_image_url}
+                    alt={`${theme.name} Preview`}
+                    style={{ objectFit: "cover" }}
+                    fill
+                  />
+                ) : (
+                  <div className="flex items-center justify-center h-full text-gray-400">
+                    <PaletteIcon className="h-12 w-12" />
+                  </div>
+                )}
+              </CardHeader>
+              <CardContent className="flex-grow p-4">
+                <CardTitle className="text-lg truncate">{theme.name}</CardTitle>
+                <CardDescription className="line-clamp-2">
+                  {theme.description || "No description provided."}
+                </CardDescription>
+              </CardContent>
+              <CardFooter className="flex flex-col gap-2 p-4 border-t border-gray-200 dark:border-gray-700">
+                <div className="flex gap-2">
+                  {theme.background_image_url && (
+                    <Badge>Background Image</Badge>
+                  )}
+                  {theme.foreground_image_url && (
+                    <Badge>Foreground Image</Badge>
+                  )}
+                </div>
+                <Button variant="outline" size="sm" asChild className="w-full">
+                  <Link href={`/dashboard/event-themes/${theme.id}`}>
+                    Edit Theme
+                  </Link>
+                </Button>
+              </CardFooter>
+            </Card>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}

frontend/src/app/(main)/dashboard/page.tsx

@@ -35,9 +35,14 @@ export default function DashboardPage() {
               Manage your scheduled events.
             </p>
           </div>
-          <Button asChild>
-            <Link href="/dashboard/events/new">+ Add New Event</Link>
-          </Button>
+          <div className="flex gap-2">
+            <Button variant="outline" asChild>
+              <Link href="/dashboard/event-themes">Manage Themes</Link>
+            </Button>
+            <Button asChild>
+              <Link href="/dashboard/events/new">+ Add New Event</Link>
+            </Button>
+          </div>
         </div>
 
         {isLoadingUserEvents && (