feat: tap-to-preview stickers in gallery with glow effect

Add full rarity glow to gallery stickers matching the reward popup style.
Tapping an owned sticker opens a large preview card. Allow calendar
stickers to overdraw their cell on hover.

src/lib/components/tasks/StickerCalendar.svelte

@@ -155,7 +155,6 @@
     border-radius: 8px;
     border: 1px solid transparent;
     transition: background 120ms;
-    overflow: hidden;
   }
   .cal-day.outside {
     opacity: 0.25;

src/lib/components/tasks/StickerPopup.svelte

@@ -3,7 +3,7 @@
   import { elasticOut } from 'svelte/easing';
   import { getRarityColor } from '$lib/utils/stickers';
 
-  let { sticker, onclose } = $props();
+  let { sticker, onclose, title = 'Sticker erhalten!', buttonText = 'Toll!', bounce = true } = $props();
 
   const rarityLabels = /** @type {Record<string, string>} */ ({
     common: 'Gewöhnlich',
@@ -17,19 +17,21 @@
 <div class="popup-backdrop" transition:fade={{ duration: 200 }} onclick={onclose} onkeydown={e => e.key === 'Escape' && onclose?.()}>
   <!-- svelte-ignore a11y_no_static_element_interactions -->
   <!-- svelte-ignore a11y_click_events_have_key_events -->
-  <div class="popup-card" transition:scale={{ start: 0.5, duration: 500, easing: elasticOut }} onclick={e => e.stopPropagation()}>
+  <div class="popup-card" transition:scale={bounce ? { start: 0.5, duration: 500, easing: elasticOut } : { start: 0.85, duration: 200 }} onclick={e => e.stopPropagation()}>
     <div class="sticker-display" style="--rarity-color: {getRarityColor(sticker.rarity)}">
       <img class="sticker-img" src="/stickers/{sticker.image}" alt={sticker.name} />
     </div>
     <div class="popup-text">
-      <h3>Sticker erhalten!</h3>
-      <p class="sticker-name">{sticker.name}</p>
+      <h3>{title}</h3>
+      {#if title !== sticker.name}
+        <p class="sticker-name">{sticker.name}</p>
+      {/if}
       <p class="sticker-desc">{sticker.description}</p>
       <span class="rarity-badge" style="color: {getRarityColor(sticker.rarity)}">
         {rarityLabels[sticker.rarity] || sticker.rarity}
       </span>
     </div>
-    <button class="btn-close" onclick={onclose}>Toll!</button>
+    <button class="btn-close" onclick={onclose}>{buttonText}</button>
   </div>
 </div>