Move bookmark heart from image overlay to title row in card

Heart is now next to the title text in the caption area where
it's always visible regardless of the background image.

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

src/modules/activities/components/ActivityCard.vue

@@ -92,20 +92,19 @@ const placeholderBg = computed(() => {
         {{ priceDisplay }}
       </Badge>
 
-      <!-- Bookmark button -->
+    </div>
-      <div class="absolute bottom-2 right-2">
+
+    <CardContent class="p-4 flex-1 flex flex-col gap-2">
+      <!-- Title + Bookmark -->
+      <div class="flex items-start gap-1">
+        <h3 class="font-semibold text-foreground line-clamp-2 leading-tight flex-1">
+          {{ activity.title }}
+        </h3>
         <BookmarkButton
           :pubkey="activity.organizer.pubkey"
           :d-tag="activity.id"
         />
       </div>
-    </div>
-
-    <CardContent class="p-4 flex-1 flex flex-col gap-2">
-      <!-- Title -->
-      <h3 class="font-semibold text-foreground line-clamp-2 leading-tight">
-        {{ activity.title }}
-      </h3>
 
       <!-- Summary -->
       <p