fix: 3 syntax errors in perf_bottleneck_finder.py (#211)

1. Line 116: regex pattern had broken quote escaping
2. Lines 509-510: return statement split across two lines
3. Line 524: global declaration after first use

scripts/perf_bottleneck_finder.py

@@ -113,7 +113,7 @@ def find_slow_tests_by_scan(repo_path: str) -> List[Bottleneck]:
         (r"time\.sleep\((\d+(?:\.\d+)?)\)", "Contains time.sleep() — consider using mock or async wait"),
         (r"subprocess\.run\(.*timeout=(\d+)", "Subprocess with timeout — may block test"),
         (r"requests\.(get|post|put|delete)\(", "Real HTTP call — mock with responses or httpretty"),
-        (r"open\\([^)]*)[\x27\x22]w[\x27\x22]", "File I/O in test — use tmp_path fixture"),
+        (r'open\([^)]*[\x27\x22]w[\x27\x22]', "File I/O in test — use tmp_path fixture"),
     ]
 
     for root, dirs, files in os.walk(repo_path):
@@ -521,8 +521,8 @@ def main():
                         help="Slow test threshold in seconds")
     args = parser.parse_args()
 
-    # Threshold override handled via module-level default
-    # (scan_tests uses SLOW_TEST_THRESHOLD_S from module scope)
+    # SLOW_TEST_THRESHOLD_S is module-level
+    SLOW_TEST_THRESHOLD_S = args.threshold
 
     if not os.path.isdir(args.repo):
         print(f"Error: {args.repo} is not a directory", file=sys.stderr)