feat: support configurable card variables and layouts

ai_knowledge_base_v2/apps/backend/alembic/versions/0035_content_generation_variables.py

@@ -0,0 +1,24 @@
+"""add configurable variables to content generation configs
+
+Revision ID: 0035_content_gen_variables
+Revises: 0034_agent_batch_concurrency
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+
+revision = "0035_content_gen_variables"
+down_revision = "0034_agent_batch_concurrency"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column("sys_content_generation_config", sa.Column("variables_json", sa.Text(), nullable=True))
+    op.execute("UPDATE sys_content_generation_config SET variables_json = '[]' WHERE variables_json IS NULL")
+    op.alter_column("sys_content_generation_config", "variables_json", existing_type=sa.Text(), nullable=False)
+
+
+def downgrade() -> None:
+    op.drop_column("sys_content_generation_config", "variables_json")