restructure and test, pure python and rust transport both _work_

tests/test_config.py

@@ -10,8 +10,10 @@ from cht.config import (
     STREAM_HOST,
     STREAM_PORT,
     SCENE_THRESHOLD,
-    MAX_FRAME_INTERVAL,
+    SCENE_FLUSH_FRAMES,
     SEGMENT_DURATION,
+    AUDIO_EXTRACT_INTERVAL,
+    AUDIO_SAFETY_MARGIN,
 )
 
 
@@ -41,8 +43,13 @@ def test_scene_threshold_range():
     assert 0 < SCENE_THRESHOLD < 1
 
 
-def test_max_frame_interval_positive():
-    assert MAX_FRAME_INTERVAL > 0
+def test_scene_flush_frames_non_negative():
+    assert SCENE_FLUSH_FRAMES >= 0
+
+
+def test_audio_intervals_positive():
+    assert AUDIO_EXTRACT_INTERVAL > 0
+    assert AUDIO_SAFETY_MARGIN > 0
 
 
 def test_segment_duration_positive():