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/repositories/activity_repo.py

@@ -1,4 +1,5 @@
 """Repository helpers for deal activities."""
+
 from __future__ import annotations
 
 from collections.abc import Sequence
@@ -39,7 +40,9 @@ class ActivityRepository:
         stmt = (
             select(Activity)
             .join(Deal, Deal.id == Activity.deal_id)
-            .where(Activity.deal_id == params.deal_id, Deal.organization_id == params.organization_id)
+            .where(
+                Activity.deal_id == params.deal_id, Deal.organization_id == params.organization_id
+            )
             .order_by(Activity.created_at)
         )
         stmt = self._apply_window(stmt, params)