feat(kol): support multiple platform hints with shared tag renderer

Turn the KOL prompt platform hint into a multi-select backed by the
media platforms API, persist hints as a 、-joined string, and add a
reusable KolPlatformTags component so manage/generate/package/template/
workspace views and the generate-task drawer all render the hints
consistently with truncation and overflow handling.

Also auto-select the first available subscription prompt in
GenerateTaskDrawer when switching to the subscription-prompt target so
users land on a usable option without an extra click.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/admin-web/src/views/KolManageView.vue

@@ -16,6 +16,7 @@ import { computed, ref } from 'vue'
 import { useI18n } from 'vue-i18n'
 
 import KolPackageFormModal from '@/components/kol/KolPackageFormModal.vue'
+import KolPlatformTags from '@/components/kol/KolPlatformTags.vue'
 import KolPromptEditor from '@/components/kol/KolPromptEditor.vue'
 import KolPromptFormModal from '@/components/kol/KolPromptFormModal.vue'
 import { kolManageApi } from '@/lib/api'
@@ -400,9 +401,11 @@ function canCancelSelfSubscription(pkg: KolPackageSummary) {
           >
             <template #bodyCell="{ column, record }">
               <template v-if="column.key === 'platform_hint'">
-                <a-tag color="blue">
-                  {{ record.platform_hint || t('kol.manage.platformHintDefault') }}
-                </a-tag>
+                <KolPlatformTags
+                  :value="record.platform_hint || t('kol.manage.platformHintDefault')"
+                  :max="3"
+                  size="small"
+                />
               </template>
               <template v-else-if="column.key === 'status'">
                 <a-tag