feat(ECR-026): OpsCMS ScheduledPublication 只读并 Closed

定时发布目录（ops_scheduled_publications），并加固 catalog 生成器。

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/migrations/000027_ops_scheduled_publications.down.sql

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+DROP TABLE IF EXISTS ops_scheduled_publications;

apps/api/migrations/000027_ops_scheduled_publications.up.sql

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+-- ECR-026 ScheduledPublication (read catalog)
+
+CREATE TABLE IF NOT EXISTS ops_scheduled_publications (
+  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+  code varchar(64) NOT NULL UNIQUE,
+  title varchar(128) NOT NULL,
+  target_kind varchar(32) NOT NULL CHECK (target_kind IN ('banner','feed_slot')),
+  target_code varchar(64) NOT NULL,
+  active boolean NOT NULL DEFAULT true,
+  system boolean NOT NULL DEFAULT false,
+  created_at timestamptz NOT NULL DEFAULT now(),
+  updated_at timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS idx_ops_scheduled_publications_active ON ops_scheduled_publications(active);
+
+INSERT INTO ops_scheduled_publications(code, title, target_kind, target_code, active, system)
+VALUES ('home_banner_week', '首页横幅周排期占位', 'banner', 'home_promo', true, true)
+ON CONFLICT (code) DO NOTHING;