Add pyproject.toml for consolidated project configuration and replace Black, isort, and Flake8 with Ruff

- 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.

backend/app/api/main.py

@@ -1,10 +1,12 @@
 from fastapi import APIRouter
 
-from app.api.routes import auth, users, sessions, admin, organizations
+from app.api.routes import admin, auth, organizations, sessions, users
 
 api_router = APIRouter()
 api_router.include_router(auth.router, prefix="/auth", tags=["Authentication"])
 api_router.include_router(users.router, prefix="/users", tags=["Users"])
 api_router.include_router(sessions.router, prefix="/sessions", tags=["Sessions"])
 api_router.include_router(admin.router, prefix="/admin", tags=["Admin"])
-api_router.include_router(organizations.router, prefix="/organizations", tags=["Organizations"])
+api_router.include_router(
+    organizations.router, prefix="/organizations", tags=["Organizations"]
+)