fix: review round 3 -- line length compliance across playground modules

Fixed 4 lines exceeding 120 char limit in validation.py and search.py.
All playground modules now pass PEP8 120-char max.

Skipped (duplicates 4th+ time): sync Redis calls in async endpoints,
create_session cookie flow. count_code_files fallback to size estimate
is intentional -- tree API fails for large valid repos.

289 tests pass.

Author: DevanshuNEU

backend/routes/playground/search.py

@@ -98,7 +98,11 @@ def _validate_user_repo_access(
                         expired_at=indexed_repo.get("expires_at"), session_token=token_preview)
         raise HTTPException(
             status_code=410,
-            detail={"error": "repo_expired", "message": "Repository index expired. Re-index to continue searching.", "can_reindex": True}
+            detail={
+                "error": "repo_expired",
+                "message": "Repository index expired. Re-index to continue searching.",
+                "can_reindex": True,
+            }
         )
 
     logger.info("Search on user-indexed repo", repo_id=repo_id[:16],
@@ -204,9 +208,21 @@ async def list_playground_repos() -> dict:
     """List available demo repositories."""
     return {
         "repos": [
-            {"id": "flask", "name": "Flask", "description": "Python web framework", "available": "flask" in DEMO_REPO_IDS},
-            {"id": "fastapi", "name": "FastAPI", "description": "Modern Python API", "available": "fastapi" in DEMO_REPO_IDS},
-            {"id": "express", "name": "Express", "description": "Node.js framework", "available": "express" in DEMO_REPO_IDS},
+            {
+                "id": "flask", "name": "Flask",
+                "description": "Python web framework",
+                "available": "flask" in DEMO_REPO_IDS,
+            },
+            {
+                "id": "fastapi", "name": "FastAPI",
+                "description": "Modern Python API",
+                "available": "fastapi" in DEMO_REPO_IDS,
+            },
+            {
+                "id": "express", "name": "Express",
+                "description": "Node.js framework",
+                "available": "express" in DEMO_REPO_IDS,
+            },
         ]
     }
 

backend/routes/playground/validation.py

@@ -137,7 +137,10 @@ async def validate_github_repo(request: ValidateRepoRequest) -> dict:
         elif error_type == "rate_limited":
             raise HTTPException(status_code=429, detail={"message": "GitHub API rate limit exceeded. Try again later."})
         else:
-            raise HTTPException(status_code=502, detail={"message": metadata.get("message", "Failed to fetch repository info")})
+            raise HTTPException(
+                status_code=502,
+                detail={"message": metadata.get("message", "Failed to fetch repository info")},
+            )
 
     if metadata.get("private", False):
         return {