fix(ui): improve group selector dropdown width and visibility

- Increase Select dropdown max-width from 320px to 480px for better content display
- Change KeysView group selector from fixed 256px to adaptive 280-480px width
- Make group switch icon always visible (60% opacity, 100% on hover)
- Allow group description to wrap to 2 lines instead of truncating
- Improve user experience for group selection in API keys page

frontend/src/views/user/KeysView.vue

@@ -102,7 +102,7 @@
                   t('keys.noGroup')
                 }}</span>
                 <svg
-                  class="h-3.5 w-3.5 text-gray-400 opacity-0 transition-opacity group-hover/dropdown:opacity-100"
+                  class="h-3.5 w-3.5 text-gray-400 opacity-60 transition-opacity group-hover/dropdown:opacity-100"
                   fill="none"
                   stroke="currentColor"
                   viewBox="0 0 24 24"
@@ -955,7 +955,7 @@
       <div
         v-if="groupSelectorKeyId !== null && dropdownPosition"
         ref="dropdownRef"
-        class="animate-in fade-in slide-in-from-top-2 fixed z-[100000020] w-64 overflow-hidden rounded-xl bg-white shadow-lg ring-1 ring-black/5 duration-200 dark:bg-dark-800 dark:ring-white/10"
+        class="animate-in fade-in slide-in-from-top-2 fixed z-[100000020] w-auto min-w-[280px] max-w-[480px] overflow-hidden rounded-xl bg-white shadow-lg ring-1 ring-black/5 duration-200 dark:bg-dark-800 dark:ring-white/10"
         style="pointer-events: auto !important;"
         :style="{ top: dropdownPosition.top + 'px', left: dropdownPosition.left + 'px' }"
       >