refactor: modernize code quality tooling with Ruff

- Replace black, isort, and flake8 with Ruff (all-in-one linter and formatter)
- Add comprehensive pyproject.toml configuration
- Simplify Makefile code quality targets
- Configure exclusions for venv/.venv in pyproject.toml
- Auto-fix 1,359 linting issues across codebase

Benefits:
- Much faster builds (Ruff is written in Rust)
- Single tool replaces multiple tools
- More comprehensive rule set (UP, B, C4, SIM, PIE, RET, Q)
- All configuration centralized in pyproject.toml
- Better import sorting and formatting consistency

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/unit/middleware/test_auth.py

@@ -12,17 +12,21 @@ Tests cover:
 - Error handling and edge cases
 """
 
-from datetime import datetime, timedelta, timezone
-from unittest.mock import MagicMock, Mock, patch
+from datetime import UTC, datetime, timedelta
+from unittest.mock import Mock, patch
 
 import pytest
 from fastapi import HTTPException
 from jose import jwt
 
-from app.exceptions import (AdminRequiredException,
-                            InsufficientPermissionsException,
-                            InvalidCredentialsException, InvalidTokenException,
-                            TokenExpiredException, UserNotActiveException)
+from app.exceptions import (
+    AdminRequiredException,
+    InsufficientPermissionsException,
+    InvalidCredentialsException,
+    InvalidTokenException,
+    TokenExpiredException,
+    UserNotActiveException,
+)
 from middleware.auth import AuthManager
 from models.database.user import User
 
@@ -316,7 +320,7 @@ class TestJWTTokenVerification:
         # Create token without 'sub' field
         payload = {
             "username": "testuser",
-            "exp": datetime.now(timezone.utc) + timedelta(minutes=30),
+            "exp": datetime.now(UTC) + timedelta(minutes=30),
         }
         token = jwt.encode(
             payload, auth_manager.secret_key, algorithm=auth_manager.algorithm
@@ -349,7 +353,7 @@ class TestJWTTokenVerification:
         payload = {
             "sub": "1",
             "username": "testuser",
-            "exp": datetime.now(timezone.utc) + timedelta(minutes=30),
+            "exp": datetime.now(UTC) + timedelta(minutes=30),
         }
         # Create token with different algorithm
         token = jwt.encode(payload, auth_manager.secret_key, algorithm="HS512")
@@ -362,7 +366,7 @@ class TestJWTTokenVerification:
         auth_manager = AuthManager()
 
         # Create a token with expiration in the past
-        past_time = datetime.now(timezone.utc) - timedelta(minutes=1)
+        past_time = datetime.now(UTC) - timedelta(minutes=1)
         payload = {"sub": "1", "username": "testuser", "exp": past_time.timestamp()}
         token = jwt.encode(
             payload, auth_manager.secret_key, algorithm=auth_manager.algorithm
@@ -661,8 +665,8 @@ class TestEdgeCases:
         payload = {
             "sub": "1",
             "username": "testuser",
-            "iat": datetime.now(timezone.utc) + timedelta(hours=1),  # Future time
-            "exp": datetime.now(timezone.utc) + timedelta(hours=2),
+            "iat": datetime.now(UTC) + timedelta(hours=1),  # Future time
+            "exp": datetime.now(UTC) + timedelta(hours=2),
         }
         token = jwt.encode(
             payload, auth_manager.secret_key, algorithm=auth_manager.algorithm