refactor: restructure project into layered architecture

backend/alembic/versions/96dff3d4cf1c_initial.py

@@ -0,0 +1,28 @@
+"""initial
+
+Revision ID: 96dff3d4cf1c
+Revises: 
+Create Date: 2026-05-17 03:07:55.231096
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = '96dff3d4cf1c'
+down_revision: Union[str, Sequence[str], None] = None
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    pass
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    pass