feat: 게시판 공지 UI (관리자) — 작성 체크박스/상세 토글/목록 배지

- BoardWriteView: 관리자가 커뮤니티 새 글 작성 시 '공지로 등록' 체크박스
- BoardDetailView: 관리자 공지 등록/해제 버튼 + 제목 공지 배지
- BoardListView: 공지 배지 + 행 강조(최상단은 백엔드 정렬)
- boardApi: setNotice/unsetNotice

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

src/views/board/BoardWriteView.vue

@@ -2,19 +2,25 @@
 import { onMounted, ref, computed } from 'vue'
 import { useRoute, useRouter } from 'vue-router'
 import { boardApi } from '@/api/boardApi'
+import { useAuthStore } from '@/stores/auth'
 import MarkdownEditor from '@/components/editor/MarkdownEditor.vue'
 import IconBtn from '@/components/ui/IconBtn.vue'
 import { DEFAULT_BOARD } from '@/constants/boards'
 
 const route = useRoute()
 const router = useRouter()
+const auth = useAuthStore()
 
 const category = route.params.category || DEFAULT_BOARD
 const editId = route.params.id || null
 const isEdit = computed(() => !!editId)
+// 공지: 관리자가 커뮤니티 게시판에 새 글 작성할 때만 설정 가능
+const isAdmin = computed(() => auth.user?.role === 'ADMIN')
+const canNotice = computed(() => isAdmin.value && category === 'community' && !isEdit.value)
 
 const title = ref('')
 const content = ref('')
+const notice = ref(false)
 const tagGroups = ref([])
 const selectedTagIds = ref([])
 const loading = ref(false)
@@ -65,6 +71,7 @@ async function submit() {
     title: title.value.trim(),
     content: content.value,
     category,
+    notice: canNotice.value ? notice.value : false,
     tagIds: selectedTagIds.value,
   }
   try {
@@ -97,6 +104,12 @@ onMounted(async () => {
     <form class="write-form" @submit.prevent="submit">
       <input v-model="title" type="text" placeholder="제목" maxlength="200" :disabled="loading" />
 
+      <!-- 공지 등록 (관리자, 커뮤니티 새 글) -->
+      <label v-if="canNotice" class="notice-check">
+        <input v-model="notice" type="checkbox" :disabled="loading" />
+        📌 공지로 등록 (목록 최상단 고정)
+      </label>
+
       <!-- 태그 선택 (DB 등록 태그를 뱃지로 토글) -->
       <div class="tag-select">
         <div v-if="!allTags.length" class="hint">
@@ -178,6 +191,17 @@ h1 {
   font-size: 0.85rem;
   opacity: 0.65;
 }
+.notice-check {
+  display: flex;
+  align-items: center;
+  gap: 0.4rem;
+  font-size: 0.9rem;
+  cursor: pointer;
+}
+.notice-check input {
+  width: auto;
+  cursor: pointer;
+}
 .buttons {
   display: flex;
   justify-content: flex-end;