Add initial models and database tables

This migration introduces all initial database models and their respective tables, relationships, and constraints. It includes entities such as users, events, guests, themes, media, and various related entities to support application functionality. This serves as a foundational schema for the project.

backend/app/alembic/versions/7396957cbe80_initial_empty_migration.py

@@ -0,0 +1,26 @@
+"""Initial empty migration
+
+Revision ID: 7396957cbe80
+Revises: 
+Create Date: 2025-02-27 12:47:46.445313
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = '7396957cbe80'
+down_revision: Union[str, None] = None
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    pass
+
+
+def downgrade() -> None:
+    pass