This commit addresses issues with backend models, schemas, and migrations.
Key changes:
- Consolidated all SQLAlchemy model definitions into `be/app/models.py`.
- Emptied `be/app/models/expense.py` as its contents were duplicates.
- Verified and standardized Base class usage and SQLAlchemy imports in models.
- Confirmed the correctness of self-referential relationships in the `Expense` model.
- Added a clarifying comment to `SplitTypeEnum` regarding future extensibility.
- Corrected a typo in `Settlement.created_by_user_id`.
Migration Cleanup:
- Deleted all existing Alembic migration files from `be/alembic/versions/`.
- Created a new, single initial migration script (`0001_initial_schema.py`) that defines the entire database schema based on the current state of the SQLAlchemy models. This provides a clean slate for future migrations.
This reset was performed because the previous migration history was complex and contained a revision that was incompatible with the current model definitions. Starting fresh ensures consistency between the models and the database schema from the initial point.
