Remove CLS collection and support a full news AI reset

backend/alembic/versions/20261104_c91234567890_remove_cls.py

@@ -0,0 +1,17 @@
+"""Retire CLS sources after explicitly authorized operator cleanup."""
+from alembic import op
+import sqlalchemy as sa
+
+revision = 'c91234567890'
+down_revision = 'b81234567890'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Existing foreign keys reject retirement until source data is removed.
+    op.execute(sa.text("DELETE FROM sources WHERE code IN ('cls_depth', 'cls_telegraph')"))
+
+
+def downgrade():
+    raise RuntimeError('财联社退役及已删除的数据不能通过降级恢复')