[add] migration script

api/migrations/versions/05a681a6ca93_202603231611.py

@@ -0,0 +1,32 @@
+"""202603231611
+
+Revision ID: 05a681a6ca93
+Revises: 74b51dfece29
+Create Date: 2026-03-23 16:12:44.110292
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = '05a681a6ca93'
+down_revision: Union[str, None] = '74b51dfece29'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_users_username'), table_name='users')
+    op.create_index(op.f('ix_users_username'), 'users', ['username'], unique=False)
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_users_username'), table_name='users')
+    op.create_index(op.f('ix_users_username'), 'users', ['username'], unique=True)
+    # ### end Alembic commands ###