diff --git a/backend/config/api.py b/backend/config/api.py
index 4bff8ef..1c2a770 100644
--- a/backend/config/api.py
+++ b/backend/config/api.py
@@ -5,15 +5,11 @@
 Example: "v1" -> "v2" will change /api/v1/* to /api/v2/*
 """
 
-# =============================================================================
 # API VERSION CONFIGURATION
-# =============================================================================
 
 API_VERSION = "v1"
 
-# =============================================================================
 # DERIVED PREFIXES (auto-calculated from version)
-# =============================================================================
 
 # Current versioned API prefix: /api/v1
 API_PREFIX = f"/api/{API_VERSION}"
@@ -22,9 +18,7 @@
 # Routes here will be deprecated but still functional
 LEGACY_API_PREFIX = "/api"
 
-# =============================================================================
 # DEPRECATION SETTINGS
-# =============================================================================
 
 # When True, legacy routes (/api/*) will include deprecation warning headers
 LEGACY_DEPRECATION_ENABLED = True
@@ -33,9 +27,7 @@
 DEPRECATION_HEADER = "X-API-Deprecated"
 DEPRECATION_MESSAGE = f"This endpoint is deprecated. Please use {API_PREFIX} instead."
 
-# =============================================================================
 # HELPER FUNCTIONS
-# =============================================================================
 
 def get_versioned_prefix() -> str:
     """Get the current versioned API prefix."""
diff --git a/backend/dependencies.py b/backend/dependencies.py
index 6dd84e5..26937c9 100644
--- a/backend/dependencies.py
+++ b/backend/dependencies.py
@@ -3,10 +3,6 @@
 All route modules import from here to avoid circular imports.
 """
 from fastapi import HTTPException, Depends
-from dotenv import load_dotenv
-
-# Load env vars first
-load_dotenv()
 
 from services.indexer_optimized import OptimizedCodeIndexer
 from services.repo_manager import RepositoryManager
diff --git a/backend/main.py b/backend/main.py
index ea5eb45..4eafc49 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -2,6 +2,10 @@
 CodeIntel Backend API
 FastAPI backend for codebase intelligence
 """
+# Load env vars once, before any service reads them
+from dotenv import load_dotenv
+load_dotenv()
+
 from contextlib import asynccontextmanager
 from fastapi import FastAPI, Request
 from fastapi.middleware.cors import CORSMiddleware
@@ -51,8 +55,7 @@ async def lifespan(app: FastAPI):
 )
 
 
-# ===== MIDDLEWARE =====
-
+# MIDDLEWARE
 class RequestSizeLimitMiddleware(BaseHTTPMiddleware):
     """Limit request body size to prevent abuse."""
     MAX_REQUEST_SIZE = 10 * 1024 * 1024  # 10MB
@@ -81,7 +84,7 @@ async def dispatch(self, request: Request, call_next):
 )
 
 
-# ===== ROUTERS =====
+# ROUTERS
 # All API routes are prefixed with API_PREFIX (e.g., /api/v1)
 # Route files define their sub-path (e.g., /auth, /repos)
 # Final paths: /api/v1/auth, /api/v1/repos, etc.
@@ -104,8 +107,7 @@ async def dispatch(self, request: Request, call_next):
 app.add_api_websocket_route(f"{API_PREFIX}/ws/repos/{{repo_id}}/indexing", websocket_repo_indexing)
 
 
-# ===== ERROR HANDLERS =====
-
+# ERROR HANDLERS
 @app.exception_handler(RequestValidationError)
 async def validation_exception_handler(request: Request, exc: RequestValidationError):
     """Handle validation errors with clear messages."""
diff --git a/backend/middleware/auth.py b/backend/middleware/auth.py
index d8a3a1e..7aff83a 100644
--- a/backend/middleware/auth.py
+++ b/backend/middleware/auth.py
@@ -29,9 +29,7 @@ async def demo_search(auth: AuthContext = Depends(public_auth)):
 from fastapi.security.http import HTTPAuthorizationCredentials
 
 
-# ---------------------------------------------------------------------------
 # Auth Context - unified return type for all auth methods
-# ---------------------------------------------------------------------------
 
 @dataclass
 class AuthContext:
@@ -52,17 +50,13 @@ def identifier(self) -> str:
         return self.user_id or self.api_key_name or "anonymous"
 
 
-# ---------------------------------------------------------------------------
 # Bearer token scheme (auto_error=False allows optional auth)
-# ---------------------------------------------------------------------------
 
 _bearer = HTTPBearer(auto_error=False)
 _bearer_required = HTTPBearer(auto_error=True)
 
 
-# ---------------------------------------------------------------------------
 # Core validation functions
-# ---------------------------------------------------------------------------
 
 def _validate_jwt(token: str) -> Optional[AuthContext]:
     """Validate Supabase JWT token"""
@@ -143,9 +137,7 @@ def _authenticate(token: str) -> AuthContext:
     )
 
 
-# ---------------------------------------------------------------------------
 # FastAPI Dependencies - use these in your routes
-# ---------------------------------------------------------------------------
 
 async def require_auth(
     credentials: HTTPAuthorizationCredentials = Depends(_bearer_required)
@@ -177,9 +169,7 @@ async def public_auth(
         return AuthContext(is_public=True)
 
 
-# ---------------------------------------------------------------------------
 # Legacy functions - kept for backwards compatibility
-# ---------------------------------------------------------------------------
 
 async def get_current_user(
     credentials: HTTPAuthorizationCredentials = Depends(_bearer_required)
diff --git a/backend/routes/playground.py b/backend/routes/playground.py
index c3dda66..e7ccacf 100644
--- a/backend/routes/playground.py
+++ b/backend/routes/playground.py
@@ -785,9 +785,7 @@ async def validate_github_repo(request: ValidateRepoRequest, req: Request):
     return result
 
 
-# =============================================================================
 # Anonymous Indexing Endpoint (#125)
-# =============================================================================
 
 @router.post("/index", status_code=202)
 async def start_anonymous_indexing(
@@ -1030,9 +1028,7 @@ async def start_anonymous_indexing(
     return response_data
 
 
-# =============================================================================
 # GET /playground/index/{job_id} - Check indexing job status (#126)
-# =============================================================================
 
 @router.get(
     "/index/{job_id}",
diff --git a/backend/services/cache.py b/backend/services/cache.py
index 0ff2790..e6d6bff 100644
--- a/backend/services/cache.py
+++ b/backend/services/cache.py
@@ -7,12 +7,9 @@
 import hashlib
 from typing import Optional, List, Dict
 import os
-from dotenv import load_dotenv
 
 from services.observability import logger, metrics
 
-load_dotenv()
-
 # Configuration
 REDIS_URL = os.getenv("REDIS_URL")  # Railway/Cloud Redis URL
 REDIS_HOST = os.getenv("REDIS_HOST", "localhost")
diff --git a/backend/services/dependency_analyzer.py b/backend/services/dependency_analyzer.py
index bad75a8..8dddcac 100644
--- a/backend/services/dependency_analyzer.py
+++ b/backend/services/dependency_analyzer.py
@@ -399,8 +399,7 @@ def _find_test_files(self, file_path: str, nodes: List[Dict]) -> List[str]:
         return test_files
 
     
-    # ===== SUPABASE CACHING =====
-    
+    # SUPABASE CACHING
     def save_to_cache(self, repo_id: str, graph_data: Dict):
         """Save dependency graph to Supabase for caching"""
         from services.supabase_service import get_supabase_service
diff --git a/backend/services/indexer_optimized.py b/backend/services/indexer_optimized.py
index 9317488..c364f5a 100644
--- a/backend/services/indexer_optimized.py
+++ b/backend/services/indexer_optimized.py
@@ -27,7 +27,6 @@
 
 # Utils
 import hashlib
-from dotenv import load_dotenv
 import time
 
 # Search enhancement
@@ -39,8 +38,6 @@
 # Observability
 from services.observability import logger, trace_operation, track_time, capture_exception, add_breadcrumb, metrics
 
-load_dotenv()
-
 # Configuration
 # Note: If using existing Pinecone index, match the dimension (1536 for small, 3072 for large)
 EMBEDDING_MODEL = os.getenv("EMBEDDING_MODEL", "text-embedding-3-small")
diff --git a/backend/services/observability.py b/backend/services/observability.py
index 3ca1c82..645ceec 100644
--- a/backend/services/observability.py
+++ b/backend/services/observability.py
@@ -30,9 +30,7 @@ async def index_repo(repo_id: str):
 LOG_LEVEL = os.getenv("LOG_LEVEL", "INFO" if IS_PRODUCTION else "DEBUG")
 
 
-# =============================================================================
 # STRUCTURED LOGGER
-# =============================================================================
 
 class StructuredLogger:
     """
@@ -112,9 +110,7 @@ def critical(self, message: str, **kwargs):
 logger = StructuredLogger()
 
 
-# =============================================================================
 # SENTRY INTEGRATION HELPERS
-# =============================================================================
 
 def set_operation_context(operation: str, **kwargs):
     """
@@ -191,9 +187,7 @@ def capture_message(message: str, level: str = "info", **context):
         pass
 
 
-# =============================================================================
 # PERFORMANCE TRACKING
-# =============================================================================
 
 @contextmanager
 def track_time(operation: str, **tags):
@@ -307,9 +301,7 @@ def sync_wrapper(*args, **kwargs):
     return decorator
 
 
-# =============================================================================
 # SIMPLE METRICS (in-memory counters)
-# =============================================================================
 
 class Metrics:
     """
diff --git a/backend/services/playground_limiter.py b/backend/services/playground_limiter.py
index 91f595d..817c52b 100644
--- a/backend/services/playground_limiter.py
+++ b/backend/services/playground_limiter.py
@@ -25,9 +25,7 @@
 from services.sentry import capture_exception
 
 
-# =============================================================================
 # DATA CLASSES
-# =============================================================================
 
 @dataclass
 class PlaygroundLimitResult:
@@ -134,9 +132,7 @@ def _truncate_id(session_id: str) -> str:
         return session_id
 
 
-# =============================================================================
 # MAIN CLASS
-# =============================================================================
 
 class PlaygroundLimiter:
     """
@@ -161,9 +157,7 @@ class PlaygroundLimiter:
         has_repo = limiter.has_indexed_repo(session_token)
     """
 
-    # -------------------------------------------------------------------------
     # Configuration
-    # -------------------------------------------------------------------------
 
     # Rate limits
     SESSION_LIMIT_PER_DAY = 50      # Per device (generous for conversion)
@@ -198,9 +192,7 @@ def __init__(self, redis_client=None):
         """
         self.redis = redis_client
 
-    # -------------------------------------------------------------------------
     # Session Data Methods (#127)
-    # -------------------------------------------------------------------------
 
     def get_session_data(self, session_token: Optional[str]) -> SessionData:
         """
@@ -449,9 +441,7 @@ def create_session(self, session_token: str) -> bool:
             capture_exception(e, operation="create_session")
             return False
 
-    # -------------------------------------------------------------------------
     # Rate Limiting Methods (existing, updated for hash storage)
-    # -------------------------------------------------------------------------
 
     def check_limit(
         self,
@@ -657,9 +647,7 @@ def _check_ip_limit(self, client_ip: str, record: bool) -> Tuple[bool, int]:
             logger.error("IP limit check failed", error=str(e))
             return True, self.IP_LIMIT_PER_DAY  # Fail open
 
-    # -------------------------------------------------------------------------
     # Helper Methods
-    # -------------------------------------------------------------------------
 
     def _get_midnight_utc(self) -> datetime:
         """Get next midnight UTC for reset time."""
@@ -788,9 +776,7 @@ def get_usage_stats(self) -> dict:
             return {"error": str(e), "redis_available": False}
 
 
-# =============================================================================
 # SINGLETON
-# =============================================================================
 
 _playground_limiter: Optional[PlaygroundLimiter] = None
 
diff --git a/backend/services/sentry.py b/backend/services/sentry.py
index 4f7dbdc..bfbddc5 100644
--- a/backend/services/sentry.py
+++ b/backend/services/sentry.py
@@ -19,7 +19,7 @@ def init_sentry() -> bool:
     sentry_dsn = os.getenv("SENTRY_DSN")
 
     if not sentry_dsn:
-        print("ℹ️  Sentry DSN not configured - error tracking disabled")
+        print("[INFO] Sentry DSN not configured - error tracking disabled")
         return False
 
     try:
@@ -61,14 +61,14 @@ def init_sentry() -> bool:
             include_local_variables=True,
         )
 
-        print(f"✅ Sentry initialized (environment: {environment})")
+        print(f"[OK] Sentry initialized (environment: {environment})")
         return True
 
     except ImportError:
-        print("⚠️  sentry-sdk not installed - error tracking disabled")
+        print("[WARN] sentry-sdk not installed - error tracking disabled")
         return False
     except Exception as e:
-        print(f"⚠️  Failed to initialize Sentry: {e}")
+        print(f"[WARN] Failed to initialize Sentry: {e}")
         return False
 
 
@@ -97,9 +97,7 @@ def _filter_events(event, hint):
     return event
 
 
-# ============================================================================
 # LEGACY FUNCTIONS - Use observability module for new code
-# ============================================================================
 
 def set_user_context(user_id: Optional[str] = None, email: Optional[str] = None):
     """
diff --git a/backend/services/style_analyzer.py b/backend/services/style_analyzer.py
index 28a584b..780496d 100644
--- a/backend/services/style_analyzer.py
+++ b/backend/services/style_analyzer.py
@@ -3,7 +3,7 @@
 Analyzes team coding patterns, naming conventions, and best practices
 """
 from pathlib import Path
-from typing import Dict, List, Set
+from typing import Dict, List, Optional, Set
 from collections import defaultdict, Counter
 import re
 
@@ -137,7 +137,7 @@ def _check_type_hints(self, source_code: str, language: str) -> bool:
         if language == 'python':
             return '->' in source_code or ': ' in source_code
         else:
-            return ': ' in source_code and 'interface' in source_code or 'type ' in source_code
+            return ': ' in source_code and ('interface' in source_code or 'type ' in source_code)
     
     def analyze_repository_style(self, repo_path: str) -> Dict:
         """Analyze coding style patterns across repository"""
@@ -263,16 +263,15 @@ def analyze_repository_style(self, repo_path: str) -> Dict:
         }
 
     
-    # ===== SUPABASE CACHING =====
-    
-    def save_to_cache(self, repo_id: str, style_data: Dict):
+    # SUPABASE CACHING
+    def save_to_cache(self, repo_id: str, style_data: Dict) -> None:
         """Save style analysis to Supabase for caching"""
         from services.supabase_service import get_supabase_service
         
         db = get_supabase_service()
         
-        # Group by language
-        for language, data in style_data.get("languages", {}).items():
+        # analyze_repository_style returns "language_distribution" not "languages"
+        for language, data in style_data.get("language_distribution", {}).items():
             analysis = {
                 "naming_convention": data.get("naming_conventions"),
                 "async_usage": data.get("async_usage"),
@@ -285,7 +284,7 @@ def save_to_cache(self, repo_id: str, style_data: Dict):
         
         logger.debug("Cached code style analysis in Supabase", repo_id=repo_id)
     
-    def load_from_cache(self, repo_id: str) -> Dict:
+    def load_from_cache(self, repo_id: str) -> Optional[Dict]:
         """Load style analysis from Supabase cache"""
         from services.supabase_service import get_supabase_service
         
@@ -319,7 +318,7 @@ def load_from_cache(self, repo_id: str) -> Dict:
         logger.debug("Loaded cached code style from Supabase", repo_id=repo_id)
         
         return {
-            "languages": languages,
+            "language_distribution": languages,
             "top_imports": common_imports,
             "patterns": patterns
         }
diff --git a/backend/services/supabase_service.py b/backend/services/supabase_service.py
index abaff71..0a8a40d 100644
--- a/backend/services/supabase_service.py
+++ b/backend/services/supabase_service.py
@@ -6,13 +6,10 @@
 from typing import Dict, List, Optional, Any
 from datetime import datetime
 from supabase import create_client, Client, ClientOptions
-from dotenv import load_dotenv
 import uuid
 
 from services.observability import logger
 
-load_dotenv()
-
 
 class SupabaseService:
     """Service for Supabase database operations"""
@@ -33,8 +30,7 @@ def __init__(self):
         self.client: Client = create_client(supabase_url, supabase_key, options)
         logger.info("Supabase service initialized")
     
-    # ===== REPOSITORIES =====
-    
+    # REPOSITORIES
     def create_repository(
         self,
         name: str,
@@ -126,8 +122,7 @@ def delete_repository(self, repo_id: str) -> None:
         """Delete repository (cascades to related tables)"""
         self.client.table("repositories").delete().eq("id", repo_id).execute()
     
-    # ===== FILE DEPENDENCIES =====
-    
+    # FILE DEPENDENCIES
     def upsert_file_dependencies(self, repo_id: str, dependencies: List[Dict]) -> None:
         """Bulk upsert file dependencies"""
         if not dependencies:
@@ -158,8 +153,7 @@ def clear_file_dependencies(self, repo_id: str) -> None:
         """Clear all file dependencies for a repo (for reindexing)"""
         self.client.table("file_dependencies").delete().eq("repo_id", repo_id).execute()
     
-    # ===== CODE STYLE ANALYSIS =====
-    
+    # CODE STYLE ANALYSIS
     def upsert_code_style(self, repo_id: str, language: str, analysis: Dict) -> None:
         """Store code style analysis results"""
         data = {
@@ -182,8 +176,7 @@ def get_code_style(self, repo_id: str) -> List[Dict]:
         result = self.client.table("code_style_analysis").select("*").eq("repo_id", repo_id).execute()
         return result.data or []
     
-    # ===== REPOSITORY INSIGHTS =====
-    
+    # REPOSITORY INSIGHTS
     def upsert_repository_insights(self, repo_id: str, insights: Dict) -> None:
         """Store repository insights"""
         data = {
@@ -206,8 +199,7 @@ def get_repository_insights(self, repo_id: str) -> Optional[Dict]:
         result = self.client.table("repository_insights").select("*").eq("repo_id", repo_id).execute()
         return result.data[0] if result.data else None
     
-    # ===== INDEXING JOBS =====
-    
+    # INDEXING JOBS
     def create_indexing_job(self, repo_id: str, total_files: int) -> str:
         """Create a new indexing job"""
         data = {
diff --git a/backend/services/user_limits.py b/backend/services/user_limits.py
index 61a2404..8075c13 100644
--- a/backend/services/user_limits.py
+++ b/backend/services/user_limits.py
@@ -139,8 +139,7 @@ def _validate_user_id(self, user_id: str) -> bool:
             return False
         return True
     
-    # ===== TIER MANAGEMENT =====
-    
+    # TIER MANAGEMENT
     def get_user_tier(self, user_id: str) -> UserTier:
         """
         Get user's current tier.
@@ -211,8 +210,7 @@ def invalidate_tier_cache(self, user_id: str) -> None:
             except Exception as e:
                 logger.warning("Failed to invalidate tier cache", error=str(e))
     
-    # ===== REPO COUNT LIMITS (#95) =====
-    
+    # REPO COUNT LIMITS (#95)
     def get_user_repo_count(self, user_id: str, raise_on_error: bool = False) -> int:
         """
         Get current repo count for user.
@@ -301,8 +299,7 @@ def check_repo_count(self, user_id: str) -> LimitCheckResult:
             tier=tier.value
         )
     
-    # ===== REPO SIZE LIMITS (#94) =====
-    
+    # REPO SIZE LIMITS (#94)
     def check_repo_size(
         self, 
         user_id: str, 
@@ -377,14 +374,12 @@ def check_repo_size(
             tier=tier.value
         )
     
-    # ===== PLAYGROUND RATE LIMITS (#93) =====
-    
+    # PLAYGROUND RATE LIMITS (#93)
     def get_playground_limit(self, tier: UserTier = UserTier.FREE) -> Optional[int]:
         """Get playground search limit for tier"""
         return self.get_limits(tier).playground_searches_per_day
     
-    # ===== USAGE SUMMARY =====
-    
+    # USAGE SUMMARY
     def get_usage_summary(self, user_id: str) -> Dict[str, Any]:
         """
         Get complete usage summary for user.
diff --git a/backend/tests/conftest.py b/backend/tests/conftest.py
index dddc112..84ca3f2 100644
--- a/backend/tests/conftest.py
+++ b/backend/tests/conftest.py
@@ -20,9 +20,7 @@
 os.environ["SUPABASE_ANON_KEY"] = "test-anon-key"
 os.environ["SUPABASE_JWT_SECRET"] = "test-jwt-secret"
 
-# =============================================================================
 # EARLY PATCHING - runs during collection, before any imports
-# =============================================================================
 # These patches prevent external service initialization during test collection
 
 _pinecone_patcher = patch('pinecone.Pinecone')
@@ -47,7 +45,6 @@
 _supabase_client.auth.get_user.return_value = _auth_response
 _mock_supabase.return_value = _supabase_client
 
-# =============================================================================
 
 # Add backend to path
 backend_dir = Path(__file__).parent.parent
diff --git a/backend/tests/test_anonymous_indexing.py b/backend/tests/test_anonymous_indexing.py
index 7d0ea47..e2160c5 100644
--- a/backend/tests/test_anonymous_indexing.py
+++ b/backend/tests/test_anonymous_indexing.py
@@ -22,9 +22,7 @@
 )
 
 
-# =============================================================================
 # REQUEST MODEL TESTS
-# =============================================================================
 
 class TestIndexRepoRequest:
     """Tests for IndexRepoRequest validation."""
@@ -76,9 +74,7 @@ def test_url_whitespace_trimmed(self):
         assert req.github_url == "https://github.com/user/repo"
 
 
-# =============================================================================
 # JOB MANAGER TESTS
-# =============================================================================
 
 class TestAnonymousIndexingJob:
     """Tests for AnonymousIndexingJob service."""
@@ -230,9 +226,7 @@ def test_update_status_failed_with_error(self, job_manager, mock_redis):
         assert result is True
 
 
-# =============================================================================
 # JOB DATACLASS TESTS
-# =============================================================================
 
 class TestJobDataclasses:
     """Tests for JobProgress and JobStats."""
@@ -268,9 +262,7 @@ def test_job_stats_to_dict(self):
         assert d["indexing_time_seconds"] == 45.5
 
 
-# =============================================================================
 # ENDPOINT TESTS (Integration)
-# =============================================================================
 
 class TestIndexEndpoint:
     """Integration tests for POST /playground/index."""
@@ -428,9 +420,7 @@ def test_github_rate_limit_returns_429(self, mock_metadata, client):
         assert response.status_code == 429
 
 
-# =============================================================================
 # SESSION CONFLICT TESTS
-# =============================================================================
 
 class TestSessionConflict:
     """Tests for session-already-has-repo behavior."""
@@ -514,9 +504,7 @@ def test_expired_repo_allows_new_indexing(
         assert response.json()["job_id"] == "idx_new123456"
 
 
-# =============================================================================
 # STATUS ENDPOINT TESTS (GET /playground/index/{job_id})
-# =============================================================================
 
 class TestStatusEndpoint:
     """Tests for GET /playground/index/{job_id} status endpoint."""
@@ -682,9 +670,7 @@ def test_partial_job_includes_partial_info(self, mock_job_class, client):
 
 
 
-# =============================================================================
 # Issue #128: Search User-Indexed Repos Tests
-# =============================================================================
 
 class TestSearchUserRepos:
     """Tests for searching user-indexed repositories."""
diff --git a/backend/tests/test_multi_tenancy.py b/backend/tests/test_multi_tenancy.py
index 17f2693..e5c334f 100644
--- a/backend/tests/test_multi_tenancy.py
+++ b/backend/tests/test_multi_tenancy.py
@@ -30,8 +30,7 @@
 sys.path.insert(0, str(backend_dir))
 
 
-# ============== TEST DATA ==============
-
+# TEST DATA
 REPOS_DB = [
     {
         "id": "repo-user1-a", "name": "User1 Repo A", "user_id": "user-1",
@@ -52,8 +51,7 @@
 ]
 
 
-# ============== UNIT TESTS FOR SUPABASE SERVICE ==============
-
+# UNIT TESTS FOR SUPABASE SERVICE
 class TestSupabaseServiceOwnership:
     """Unit tests for ownership verification methods in SupabaseService"""
 
@@ -121,8 +119,7 @@ def test_verify_repo_ownership_returns_true_for_owner(self):
         assert sig.return_annotation == bool
 
 
-# ============== UNIT TESTS FOR REPO MANAGER ==============
-
+# UNIT TESTS FOR REPO MANAGER
 class TestRepoManagerOwnership:
     """Unit tests for ownership methods in RepoManager"""
 
@@ -163,8 +160,7 @@ def test_verify_ownership_delegates_to_supabase(self):
                 assert result is False
 
 
-# ============== HELPER FUNCTION TESTS ==============
-
+# HELPER FUNCTION TESTS
 class TestSecurityHelpers:
     """Test the get_repo_or_404 and verify_repo_access helpers"""
 
@@ -200,14 +196,8 @@ def test_verify_repo_access_raises_404_for_wrong_user(self):
 
             assert exc_info.value.status_code == 404
 
-            with pytest.raises(HTTPException) as exc_info:
-                verify_repo_access("repo-user2-a", "user-1")
-
-            assert exc_info.value.status_code == 404
-
-
-# ============== DEV API KEY TESTS ==============
 
+# DEV API KEY TESTS
 class TestDevApiKeySecurity:
     """Test that dev API key is properly secured (Issue #8)"""
 
@@ -294,8 +284,7 @@ def test_wrong_dev_key_fails_even_in_debug(self):
             self._reload_auth_module()  # Reload to known good state
 
 
-# ============== INFO LEAKAGE TESTS ==============
-
+# INFO LEAKAGE TESTS
 class TestInfoLeakagePrevention:
     """Test that 404 is returned instead of 403 to prevent info leakage"""
 
@@ -318,8 +307,7 @@ def test_nonexistent_and_unauthorized_get_same_error(self):
             assert exc1.value.detail == exc2.value.detail
 
 
-# ============== INTEGRATION-STYLE TESTS ==============
-
+# INTEGRATION-STYLE TESTS
 class TestEndpointOwnershipIntegration:
     """
     These tests verify that endpoints actually call ownership verification.
diff --git a/backend/tests/test_playground_limiter.py b/backend/tests/test_playground_limiter.py
index 08d4b6a..b1339f7 100644
--- a/backend/tests/test_playground_limiter.py
+++ b/backend/tests/test_playground_limiter.py
@@ -20,9 +20,7 @@
 )
 
 
-# =============================================================================
 # FIXTURES
-# =============================================================================
 
 @pytest.fixture
 def mock_redis():
@@ -71,9 +69,7 @@ def sample_indexed_repo():
     }
 
 
-# =============================================================================
 # DATA CLASS TESTS
-# =============================================================================
 
 class TestIndexedRepoData:
     """Tests for IndexedRepoData dataclass."""
@@ -159,9 +155,7 @@ def test_truncate_id(self):
         assert SessionData._truncate_id("verylongsessiontoken123") == "verylong..."
 
 
-# =============================================================================
 # GET SESSION DATA TESTS
-# =============================================================================
 
 class TestGetSessionData:
     """Tests for get_session_data() method."""
@@ -228,9 +222,7 @@ def test_invalid_indexed_repo_json(self, limiter, mock_redis):
         assert result.searches_used == 5
 
 
-# =============================================================================
 # SET INDEXED REPO TESTS
-# =============================================================================
 
 class TestSetIndexedRepo:
     """Tests for set_indexed_repo() method."""
@@ -270,9 +262,7 @@ def test_preserves_other_fields(self, limiter, mock_redis, sample_indexed_repo):
         assert not mock_redis.set.called
 
 
-# =============================================================================
 # HAS INDEXED REPO TESTS
-# =============================================================================
 
 class TestHasIndexedRepo:
     """Tests for has_indexed_repo() method."""
@@ -303,9 +293,7 @@ def test_repo_not_exists(self, limiter, mock_redis):
         assert limiter.has_indexed_repo("token") is False
 
 
-# =============================================================================
 # CLEAR INDEXED REPO TESTS
-# =============================================================================
 
 class TestClearIndexedRepo:
     """Tests for clear_indexed_repo() method."""
@@ -325,9 +313,7 @@ def test_no_token_returns_false(self, limiter):
         assert limiter.clear_indexed_repo(None) is False
 
 
-# =============================================================================
 # LEGACY MIGRATION TESTS
-# =============================================================================
 
 class TestLegacyMigration:
     """Tests for legacy string format migration."""
@@ -366,9 +352,7 @@ def test_nonexistent_key_no_error(self, limiter, mock_redis):
         limiter._ensure_hash_format("new_token")
 
 
-# =============================================================================
 # RATE LIMITING WITH HASH STORAGE TESTS
-# =============================================================================
 
 class TestRateLimitingWithHash:
     """Tests to verify rate limiting still works with hash storage."""
@@ -404,9 +388,7 @@ def test_new_session_creates_hash(self, limiter, mock_redis):
         mock_redis.hset.assert_called()
 
 
-# =============================================================================
 # CREATE SESSION TESTS
-# =============================================================================
 
 class TestCreateSession:
     """Tests for create_session() method."""
@@ -432,9 +414,7 @@ def test_no_redis_returns_false(self, limiter_no_redis):
         assert limiter_no_redis.create_session("token") is False
 
 
-# =============================================================================
 # HELPER METHOD TESTS
-# =============================================================================
 
 class TestHelperMethods:
     """Tests for helper methods."""
@@ -462,9 +442,7 @@ def test_generate_session_token(self, limiter):
         assert len(token1) > 20  # Should be reasonably long
 
 
-# =============================================================================
 # INTEGRATION-STYLE TESTS
-# =============================================================================
 
 class TestSessionWorkflow:
     """End-to-end workflow tests."""
diff --git a/backend/tests/test_validate_repo.py b/backend/tests/test_validate_repo.py
index 03bd027..59df0a9 100644
--- a/backend/tests/test_validate_repo.py
+++ b/backend/tests/test_validate_repo.py
@@ -16,9 +16,7 @@
 )
 
 
-# =============================================================================
 # URL PARSING TESTS
-# =============================================================================
 
 class TestParseGitHubUrl:
     """Tests for URL parsing."""
@@ -89,9 +87,7 @@ def test_pattern_rejects_subpath(self):
         assert match is None
 
 
-# =============================================================================
 # REQUEST MODEL TESTS
-# =============================================================================
 
 class TestValidateRepoRequest:
     """Tests for the request model validation."""
@@ -128,9 +124,7 @@ def test_url_with_whitespace_trimmed(self):
         assert req.github_url == "https://github.com/user/repo"
 
 
-# =============================================================================
 # GITHUB API TESTS
-# =============================================================================
 
 class TestFetchRepoMetadata:
     """Tests for GitHub API interaction."""
@@ -217,9 +211,7 @@ async def test_timeout_handling(self):
             assert result["error"] == "timeout"
 
 
-# =============================================================================
 # FILE COUNTING TESTS
-# =============================================================================
 
 class TestCountCodeFiles:
     """Tests for file counting logic."""
@@ -359,9 +351,7 @@ async def test_skip_git_directory(self):
             assert error is None
 
 
-# =============================================================================
 # CONSTANTS TESTS
-# =============================================================================
 
 class TestAnonymousFileLimit:
     """Tests for file limit constant."""