Redesign public site, add phase gating and clip submission

- Rebuild landing page and Nominations/Voting/Winners views in the
  Jayuhime brand style (purple/gold/pastel-rainbow, stars, PageHero banner)
- Gate participation by season phase (nominate/clip share the nomination
  window, vote in the voting window); hide closed/locked pages from nav
- Add login-gated clip submission flow (link-based) + voting clip links
- Make candidate admin scalable: searchable, filterable, paginated table
  with modal create/edit and confirm-delete; add delete API/store actions
- New reusable Modal and PageHero components, usePhases composable
- Segmented top nav and full-size header on admin routes
- vite: honor PORT env for preview

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/components/ui/PageHero.vue

@@ -0,0 +1,59 @@
+<script setup lang="ts">
+import type { Component } from 'vue'
+import { Sparkles } from '@lucide/vue'
+
+defineProps<{
+  eyebrow: string
+  title: string
+  description?: string
+  /** Großes, dekoratives Icon oben rechts */
+  icon?: Component
+}>()
+</script>
+
+<template>
+  <section class="relative overflow-hidden rounded-[32px] border border-violet-200/60 bg-[linear-gradient(135deg,#ece2ff_0%,#f6ecff_42%,#fff2dd_100%)] px-7 py-10 shadow-[0_24px_60px_rgba(124,92,255,0.12)] sm:px-12 sm:py-14">
+    <!-- dekorativer Schein -->
+    <div class="pointer-events-none absolute inset-0 bg-[radial-gradient(circle_at_88%_18%,rgba(255,255,255,0.7),transparent_42%)]" />
+
+    <!-- Sterne -->
+    <svg class="pointer-events-none absolute inset-0 h-full w-full" aria-hidden="true">
+      <g fill="#f6b938" opacity="0.7">
+        <circle cx="74%" cy="24%" r="3" />
+        <circle cx="92%" cy="62%" r="2.5" />
+        <circle cx="63%" cy="78%" r="2.5" />
+      </g>
+      <g fill="#a78bff" opacity="0.6">
+        <circle cx="83%" cy="40%" r="2.5" />
+        <circle cx="69%" cy="50%" r="2" />
+      </g>
+    </svg>
+
+    <!-- großes dekoratives Icon -->
+    <div
+      v-if="icon"
+      class="pointer-events-none absolute -right-6 top-1/2 hidden -translate-y-1/2 sm:block"
+    >
+      <div class="grid h-44 w-44 place-items-center rounded-full bg-white/35 text-amber-400/80 ring-1 ring-white/60 backdrop-blur-sm">
+        <component :is="icon" class="h-20 w-20" />
+      </div>
+    </div>
+
+    <div class="relative max-w-2xl space-y-5">
+      <span class="inline-flex items-center gap-2 rounded-full border border-white/70 bg-white/70 px-4 py-1.5 text-[11px] font-semibold uppercase tracking-[0.3em] text-violet-600 shadow-sm backdrop-blur">
+        <Sparkles class="h-3.5 w-3.5 text-amber-500" />
+        {{ eyebrow }}
+      </span>
+
+      <h1 class="font-[Cormorant_Garamond] text-5xl leading-[0.95] text-violet-800 sm:text-6xl">
+        {{ title }}
+      </h1>
+
+      <p v-if="description" class="max-w-xl text-lg leading-8 text-slate-600">
+        {{ description }}
+      </p>
+
+      <slot name="actions" />
+    </div>
+  </section>
+</template>