Improve admin candidate modal UX and add clip menu visibility toggle

- Widen AdminCandidateEditorModal to size lg for better readability
- Rename "Clip-Compilation" section to "Clip / Compilation", update copy to reflect single clips too, drop upload hint and Clip-Plattform field, rename label to "Link"
- Fix NativeSelect dropdown clipping inside overflow-y-auto modals by teleporting the menu to body with fixed positioning, flip-up logic, and dynamic maxHeight capped to viewport
- Add ClipAdminMenuVisible setting (backend domain, contracts, endpoint, migration) with matching frontend types, defaults, form wiring, and toggle in the Clip-Workflow modal — hides the Clips nav item from the admin sidebar when disabled

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/components/home/HomeStickyCountdownPill.vue

@@ -0,0 +1,37 @@
+<template>
+  <div
+    v-if="showCountdown"
+    class="home-sticky-countdown"
+    :class="{ 'home-sticky-countdown--visible': visible }"
+    aria-live="polite"
+  >
+    <div class="home-sticky-countdown__inner">
+      <span class="home-sticky-countdown__dot" aria-hidden="true"></span>
+      <span data-dc-ref="stickyCountdownLabelRef" class="home-sticky-countdown__label">Finale startet in</span>
+      <span class="home-sticky-countdown__time" aria-label="Countdown bis zum Finale">
+        <span data-dc-ref="sbdRef">00</span><span class="home-sticky-countdown__unit">T</span>
+        <span data-dc-ref="sbhRef">00</span><span class="home-sticky-countdown__sep">:</span>
+        <span data-dc-ref="sbmRef">00</span><span class="home-sticky-countdown__sep">:</span>
+        <span data-dc-ref="sbsRef">00</span>
+      </span>
+      <a
+        v-if="showPhase"
+        :href="publicStreamUrl"
+        target="_blank"
+        rel="noopener noreferrer"
+        class="home-sticky-countdown__cta"
+      >
+        Zur Show
+      </a>
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+defineProps<{
+  showCountdown: boolean
+  visible: boolean
+  showPhase: boolean
+  publicStreamUrl: string
+}>()
+</script>