refactor: add gateway_id to agents and remove main_session_key from gateways

backend/migrations/versions/b308f2876359_sync_agent_gateway_linkage_schema.py

@@ -0,0 +1,36 @@
+"""sync agent gateway linkage schema
+
+Revision ID: b308f2876359
+Revises: a1e6b0d62f0c
+Create Date: 2026-02-10 15:49:54.395003
+
+"""
+from __future__ import annotations
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'b308f2876359'
+down_revision = 'a1e6b0d62f0c'
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('agents', sa.Column('gateway_id', sa.Uuid(), nullable=False))
+    op.create_index(op.f('ix_agents_gateway_id'), 'agents', ['gateway_id'], unique=False)
+    op.create_foreign_key(None, 'agents', 'gateways', ['gateway_id'], ['id'])
+    op.drop_column('gateways', 'main_session_key')
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('gateways', sa.Column('main_session_key', sa.VARCHAR(), autoincrement=False, nullable=False))
+    op.drop_constraint(None, 'agents', type_='foreignkey')
+    op.drop_index(op.f('ix_agents_gateway_id'), table_name='agents')
+    op.drop_column('agents', 'gateway_id')
+    # ### end Alembic commands ###