Freeze unseen music stress corpus and independently verified gated DTW experiment

tools/speech-vad/test_gated_asr.py

@@ -3,11 +3,20 @@ import copy
 import json
 from pathlib import Path
 import unittest
+from unittest.mock import patch
 
 import gated_asr as gated
 
 
 class GatedPlanning(unittest.TestCase):
+    def test_frozen_dtw_combination_preserves_sources_and_component_hashes(self):
+        plan, digest = gated.dtw_contract()
+        self.assertEqual(plan["sources"], list(gated.speech.ASSETS))
+        self.assertEqual(plan["vad_report_sha256"], gated.VAD_SHA)
+        self.assertEqual(len(digest), 64)
+        with patch.object(gated.speech, "sha256", return_value="changed"):
+            with self.assertRaises(ValueError):
+                gated.dtw_contract()
     def test_absolute_offset_and_contiguous_split(self):
         interval = gated.vad.source_intersection([10, 6110], 1000000, 5125)
         windows = gated.interval_windows([interval], 1000000, 5125)