style: apply black and isort formatting across entire codebase

- Standardize quote style (single to double quotes)
- Reorder and group imports alphabetically
- Fix line breaks and indentation for consistency
- Apply PEP 8 formatting standards

Also updated Makefile to exclude both venv and .venv from code quality checks.

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

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

tests/unit/middleware/test_rate_limiter.py

@@ -11,10 +11,11 @@ Tests cover:
 - Edge cases and concurrency scenarios
 """
 
-import pytest
-from unittest.mock import Mock, patch
-from datetime import datetime, timedelta, timezone
 from collections import deque
+from datetime import datetime, timedelta, timezone
+from unittest.mock import Mock, patch
+
+import pytest
 
 from middleware.rate_limiter import RateLimiter
 
@@ -306,8 +307,8 @@ class TestRateLimiterStatistics:
         # Add requests at different times
         now = datetime.now(timezone.utc)
         limiter.clients[client_id].append(now - timedelta(minutes=30))  # Within hour
-        limiter.clients[client_id].append(now - timedelta(hours=2))      # Within day
-        limiter.clients[client_id].append(now - timedelta(hours=12))     # Within day
+        limiter.clients[client_id].append(now - timedelta(hours=2))  # Within day
+        limiter.clients[client_id].append(now - timedelta(hours=12))  # Within day
 
         stats = limiter.get_client_stats(client_id)
 
@@ -411,7 +412,9 @@ class TestRateLimiterEdgeCases:
         limiter = RateLimiter()
         client_id = "long_window_client"
 
-        result = limiter.allow_request(client_id, max_requests=10, window_seconds=86400*365)
+        result = limiter.allow_request(
+            client_id, max_requests=10, window_seconds=86400 * 365
+        )
 
         assert result is True
 
@@ -421,10 +424,16 @@ class TestRateLimiterEdgeCases:
         client_id = "same_client"
 
         # Allow with one limit
-        assert limiter.allow_request(client_id, max_requests=10, window_seconds=3600) is True
+        assert (
+            limiter.allow_request(client_id, max_requests=10, window_seconds=3600)
+            is True
+        )
 
         # Check with stricter limit
-        assert limiter.allow_request(client_id, max_requests=1, window_seconds=3600) is False
+        assert (
+            limiter.allow_request(client_id, max_requests=1, window_seconds=3600)
+            is False
+        )
 
     def test_rate_limiter_unicode_client_id(self):
         """Test rate limiter with unicode client ID."""