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/services/organization_service.py

@@ -1,4 +1,5 @@
 """Organization-related business rules."""
+
 from __future__ import annotations
 
 from dataclasses import dataclass
@@ -54,7 +55,9 @@ class OrganizationService:
     def __init__(self, repository: OrganizationRepository) -> None:
         self._repository = repository
 
-    async def get_context(self, *, user_id: int, organization_id: int | None) -> OrganizationContext:
+    async def get_context(
+        self, *, user_id: int, organization_id: int | None
+    ) -> OrganizationContext:
         """Resolve request context ensuring the user belongs to the given organization."""
 
         if organization_id is None:
@@ -66,7 +69,9 @@ class OrganizationService:
 
         return OrganizationContext(organization=membership.organization, membership=membership)
 
-    def ensure_entity_in_context(self, *, entity_organization_id: int, context: OrganizationContext) -> None:
+    def ensure_entity_in_context(
+        self, *, entity_organization_id: int, context: OrganizationContext
+    ) -> None:
         """Make sure a resource belongs to the current organization."""
 
         if entity_organization_id != context.organization_id:
@@ -113,4 +118,4 @@ class OrganizationService:
         self._repository.session.add(membership)
         await self._repository.session.commit()
         await self._repository.session.refresh(membership)
-        return membership
+        return membership