Refactor code for improved readability and consistency

- Reformatted function signatures in `organization_service.py` and `task_service.py` for better alignment.
- Updated import statements across multiple files for consistency and organization.
- Enhanced test files by improving formatting and ensuring consistent use of async session factories.
- Added type hints and improved type safety in various service and test files.
- Adjusted `pyproject.toml` to include configuration for isort, mypy, and ruff for better code quality checks.
- Cleaned up unused imports and organized existing ones in several test files.

app/core/database.py

@@ -1,11 +1,11 @@
 """Database utilities for async SQLAlchemy engine and sessions."""
+
 from __future__ import annotations
 
 from collections.abc import AsyncGenerator
 
-from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
-
 from app.core.config import settings
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
 
 engine = create_async_engine(settings.database_url, echo=settings.sqlalchemy_echo)
 AsyncSessionMaker = async_sessionmaker(bind=engine, expire_on_commit=False)