feat(article): expose auto_publish_platforms derived from publish accounts

Replace the freeform `platforms` field on articles/tasks (parsed out of
wizard_state/input_params JSON) with `auto_publish_platforms`, resolved
by joining schedule publish accounts to platform_accounts. The migration
strips the legacy keys from existing rows so the new field is the single
source of truth.

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

apps/admin-web/src/components/ScheduleTaskTab.vue

@@ -16,6 +16,7 @@ import ScheduleTaskModal from "@/components/ScheduleTaskModal.vue";
 import { promptRulesApi, schedulesApi } from "@/lib/api";
 import { formatCronExecutionTime, formatDateTime } from "@/lib/display";
 import { formatError } from "@/lib/errors";
+import { formatPublishPlatformList } from "@/lib/publish-platforms";
 
 const queryClient = useQueryClient();
 const { t } = useI18n();
@@ -84,7 +85,7 @@ const columns = computed<TableColumnsType<ScheduleTask>>(() => [
   { title: t("custom.schedule.rule"), dataIndex: "prompt_rule_name", key: "prompt_rule_name", width: 180 },
   { title: t("custom.instant.executionStatus"), dataIndex: "status", key: "status", width: 140 },
   { title: t("custom.instant.executionTime"), dataIndex: "cron_expr", key: "cron_expr", width: 170 },
-  { title: t("custom.schedule.autoPublish"), dataIndex: "auto_publish", key: "auto_publish", width: 160 },
+  { title: t("custom.schedule.autoPublishPlatforms"), dataIndex: "auto_publish_platforms", key: "auto_publish_platforms", width: 200 },
   { title: t("custom.task.generateCount"), dataIndex: "generate_count", key: "generate_count", width: 120 },
   { title: t("custom.instant.createdTime"), dataIndex: "created_at", key: "created_at", width: 170 },
   { title: t("common.actions"), key: "actions", width: 140, fixed: "right", align: "right" },
@@ -222,11 +223,11 @@ function handleTableChange(nextPage: number, nextPageSize: number): void {
         <template v-else-if="column.key === 'cron_expr'">
           {{ formatCronExecutionTime(record.cron_expr) }}
         </template>
-        <template v-else-if="column.key === 'auto_publish'">
+        <template v-else-if="column.key === 'auto_publish_platforms'">
           <a-tag :color="record.auto_publish ? 'blue' : 'default'">
             {{
               record.auto_publish
-                ? t("custom.schedule.autoPublishAccountCount", { count: record.publish_account_ids?.length ?? 0 })
+                ? formatPublishPlatformList(record.auto_publish_platforms)
                 : t("custom.schedule.manualPublish")
             }}
           </a-tag>