feat(api): Add migration for `WorkflowDraftVariable` model

api/migrations/versions/2025_05_15_1531-2adcbe1f5dfb_add_workflowdraftvariable_model.py

@@ -0,0 +1,51 @@
+"""add WorkflowDraftVariable model
+
+Revision ID: 2adcbe1f5dfb
+Revises: d28f2004b072
+Create Date: 2025-05-15 15:31:03.128680
+
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+import models as models
+
+# revision identifiers, used by Alembic.
+revision = "2adcbe1f5dfb"
+down_revision = "d28f2004b072"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table(
+        "workflow_draft_variables",
+        sa.Column("id", models.types.StringUUID(), server_default=sa.text("uuid_generate_v4()"), nullable=False),
+        sa.Column("created_at", sa.DateTime(), server_default=sa.text("CURRENT_TIMESTAMP"), nullable=False),
+        sa.Column("updated_at", sa.DateTime(), server_default=sa.text("CURRENT_TIMESTAMP"), nullable=False),
+        sa.Column("app_id", models.types.StringUUID(), nullable=False),
+        sa.Column("last_edited_at", sa.DateTime(), nullable=True),
+        sa.Column("node_id", sa.String(length=255), nullable=False),
+        sa.Column("name", sa.String(length=255), nullable=False),
+        sa.Column("description", sa.String(length=255), nullable=False),
+        sa.Column("selector", sa.String(length=255), nullable=False),
+        sa.Column("value_type", sa.String(length=20), nullable=False),
+        sa.Column("value", sa.Text(), nullable=False),
+        sa.Column("visible", sa.Boolean(), nullable=False),
+        sa.Column("editable", sa.Boolean(), nullable=False),
+        sa.PrimaryKeyConstraint("id", name="workflow_draft_variables_pkey"),
+        sa.UniqueConstraint("app_id", "node_id", "name", name=op.f("workflow_draft_variables_app_id_key")),
+    )
+
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+
+    # Dropping `workflow_draft_variables` also drops any index associated with it.
+    op.drop_table("workflow_draft_variables")
+
+    # ### end Alembic commands ###