Address final code review nitpicks: improve code organization

Co-authored-by: denizsafak <39929354+denizsafak@users.noreply.github.com>

abogen/conversion.py

@@ -28,6 +28,9 @@ import threading  # for efficient waiting
 import subprocess
 import platform
 
+# Configuration constants
+_USER_RESPONSE_TIMEOUT = 0.1  # Timeout in seconds for checking user response/cancellation
+
 # Pre-compile frequently used regex patterns for better performance
 _METADATA_TAG_PATTERN = re.compile(r"<<METADATA_[^:]+:[^>]*>>")
 _CHAPTER_MARKER_PATTERN = re.compile(r"<<CHAPTER_MARKER:[^>]*>>")
@@ -875,10 +878,11 @@ class ConversionThread(QThread):
                     # Signal to ask user (-1 indicates timestamp detection)
                     self.chapters_detected.emit(-1)
                     # Wait for user response using event with timeout for responsive cancellation
-                    while not self._timestamp_response_event.wait(timeout=0.1):
+                    while not self._timestamp_response_event.wait(timeout=_USER_RESPONSE_TIMEOUT):
                         if self.cancel_requested:
                             self.conversion_finished.emit("Cancelled", None)
                             return
+                    # Check cancellation one more time after event is set
                     if self.cancel_requested:
                         self.conversion_finished.emit("Cancelled", None)
                         return

test_performance.py

@@ -9,6 +9,7 @@ are working correctly and don't introduce regressions.
 import re
 import time
 import sys
+import traceback
 
 
 def test_regex_precompilation_performance():
@@ -213,7 +214,6 @@ def main():
         return 1
     except Exception as e:
         print(f"\n❌ Unexpected error: {e}")
-        import traceback
         traceback.print_exc()
         return 1