Verify VAD allocation limits and decoder overshoot contracts

docs/SPEECH-VAD.md

@@ -211,6 +211,12 @@ was scored. All three native contracts passed again with the corrected build;
 four mapping regressions cover centiseconds, source origin, padded tails and
 invalid intervals. Segmentation parameters and model remained frozen.
 
+The expanded native contract suite then passed six tests in 0.471 seconds:
+missing-model failures emit no report, oversized PCM is rejected before model
+loading, and finite decoder overshoot is accepted by actual CPU inference
+without input clipping. The synthetic DC overshoot input tests the input
+contract only and is not included in the media quality pool.
+
 This small VAD-only result supports testing gated ASR next. It does not establish
 speech recall, transcript correctness, timestamp accuracy, retrieval improvement
 or a general music policy. No production gate was added and original Google