fix(db): Use UUID type in documents migration

alembic/versions/002_create_documents_table.py

@@ -18,8 +18,8 @@ depends_on = None
 def upgrade() -> None:
     # ### commands auto generated by Alembic - please adjust! ###
     op.create_table('documents',
-    sa.Column('id', sa.CHAR(36), nullable=False),
-    sa.Column('user_id', sa.CHAR(36), nullable=False),
+    sa.Column('id', sa.UUID(as_uuid=True), nullable=False),
+    sa.Column('user_id', sa.UUID(as_uuid=True), nullable=False),
     sa.Column('filename', sa.String(length=255), nullable=False),
     sa.Column('original_size', sa.Integer(), nullable=True),
     sa.Column('chunks_count', sa.Integer(), nullable=True),