feat(schedule-tasks): support auto-publish via media accounts

Replace the legacy target_platform string on schedule tasks with a
workspace-aware auto-publish payload (auto_publish + publish_account_ids
JSONB + cover_asset_url + cover_image_asset_id) and migrate the schema,
sqlc queries, generated models, domain struct, ScheduleTaskService DTOs,
and dispatch worker to round-trip the new fields. PromptRuleGeneration
gains a WithPublishJobService hook so executeGeneration can enqueue an
auto-publish job once the article is ready, and worker-generate wires
the publish-job service in. On the admin-web side, extract
PublishArticleModal's account-card builders into a shared
publish-account-cards module, rebuild GenerateTaskDrawer's schedule
mode around account selection plus a CoverPickerModal, and surface the
new "auto publish" column on ScheduleTaskTab. Shared types and i18n
strings cover the new fields.

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

server/internal/tenant/repository/queries/schedule_task.sql

@@ -1,6 +1,7 @@
 -- name: ListScheduleTasks :many
-SELECT st.id, st.tenant_id, st.prompt_rule_id, st.brand_id, st.name,
-       st.cron_expr, st.target_platform, st.start_at, st.end_at,
+SELECT st.id, st.tenant_id, st.workspace_id, st.prompt_rule_id, st.brand_id, st.name,
+       st.cron_expr, st.auto_publish, st.publish_account_ids, st.cover_asset_url, st.cover_image_asset_id,
+       st.start_at, st.end_at,
        st.next_run_at, st.status, st.created_at, st.updated_at,
        pr.name AS prompt_rule_name,
        b.name AS brand_name
@@ -23,8 +24,9 @@ WHERE tenant_id = sqlc.arg(tenant_id)
   AND (sqlc.narg(prompt_rule_id)::bigint IS NULL OR prompt_rule_id = sqlc.narg(prompt_rule_id));
 
 -- name: GetScheduleTaskByID :one
-SELECT st.id, st.tenant_id, st.prompt_rule_id, st.brand_id, st.name,
-       st.cron_expr, st.target_platform, st.start_at, st.end_at,
+SELECT st.id, st.tenant_id, st.workspace_id, st.prompt_rule_id, st.brand_id, st.name,
+       st.cron_expr, st.auto_publish, st.publish_account_ids, st.cover_asset_url, st.cover_image_asset_id,
+       st.start_at, st.end_at,
        st.next_run_at, st.status, st.created_at, st.updated_at,
        pr.name AS prompt_rule_name,
        b.name AS brand_name
@@ -34,10 +36,12 @@ LEFT JOIN brands b ON b.id = st.brand_id
 WHERE st.id = sqlc.arg(id) AND st.tenant_id = sqlc.arg(tenant_id) AND st.deleted_at IS NULL;
 
 -- name: CreateScheduleTask :one
-INSERT INTO schedule_tasks (tenant_id, prompt_rule_id, brand_id, name, cron_expr,
-                            target_platform, start_at, end_at, next_run_at)
-VALUES (sqlc.arg(tenant_id), sqlc.arg(prompt_rule_id), sqlc.narg(brand_id), sqlc.arg(name),
-        sqlc.arg(cron_expr), sqlc.narg(target_platform), sqlc.narg(start_at), sqlc.narg(end_at),
+INSERT INTO schedule_tasks (tenant_id, workspace_id, prompt_rule_id, brand_id, name, cron_expr,
+                            auto_publish, publish_account_ids, cover_asset_url, cover_image_asset_id,
+                            start_at, end_at, next_run_at)
+VALUES (sqlc.arg(tenant_id), sqlc.narg(workspace_id), sqlc.arg(prompt_rule_id), sqlc.narg(brand_id), sqlc.arg(name),
+        sqlc.arg(cron_expr), sqlc.arg(auto_publish), sqlc.arg(publish_account_ids), sqlc.narg(cover_asset_url),
+        sqlc.narg(cover_image_asset_id), sqlc.narg(start_at), sqlc.narg(end_at),
         sqlc.narg(next_run_at))
 RETURNING id, created_at;
 
@@ -45,7 +49,11 @@ RETURNING id, created_at;
 UPDATE schedule_tasks
 SET prompt_rule_id = sqlc.arg(prompt_rule_id), brand_id = sqlc.narg(brand_id),
     name = sqlc.arg(name), cron_expr = sqlc.arg(cron_expr),
-    target_platform = sqlc.narg(target_platform),
+    workspace_id = sqlc.narg(workspace_id),
+    auto_publish = sqlc.arg(auto_publish),
+    publish_account_ids = sqlc.arg(publish_account_ids),
+    cover_asset_url = sqlc.narg(cover_asset_url),
+    cover_image_asset_id = sqlc.narg(cover_image_asset_id),
     start_at = sqlc.narg(start_at), end_at = sqlc.narg(end_at),
     next_run_at = sqlc.narg(next_run_at), updated_at = NOW()
 WHERE id = sqlc.arg(id) AND tenant_id = sqlc.arg(tenant_id) AND deleted_at IS NULL;