- Added models for `OAuthClient`, `OAuthState`, and `OAuthAccount`.
- Created Pydantic schemas to support OAuth flows, client management, and linked accounts.
- Implemented skeleton endpoints for OAuth Provider mode: authorization, token, and revocation.
- Updated router imports to include new `/oauth` and `/oauth/provider` routes.
- Added Alembic migration script to create OAuth-related database tables.
- Enhanced `users` table to allow OAuth-only accounts by making `password_hash` nullable.
- Introduced `pyproject.toml` to centralize backend tool configurations (e.g., Ruff, mypy, coverage, pytest).
- Replaced Black, isort, and Flake8 with Ruff for linting, formatting, and import sorting.
- Updated `requirements.txt` to include Ruff and remove replaced tools.
- Added `Makefile` to streamline development workflows with commands for linting, formatting, type-checking, testing, and cleanup.
- Refactored all `password reset` and `auth dependency` tests to utilize async patterns for compatibility with async database sessions.
- Enhanced test fixtures with `pytest-asyncio` to support asynchronous database operations.
- Improved user handling with async context management for `test_user` and `async_mock_user`.
- Introduced `await` syntax for route calls, token generation, and database transactions in test cases.
This commit introduces a suite of tests for user models, schemas, CRUD operations, and authentication services. It also adds utilities for in-memory database setup to support these tests and updates environment settings for consistency.
