Add three encoder cosine evidence

evidence/three_encoder_teacher_cosine.json

@@ -0,0 +1,27 @@
+{
+  "format": "minimax_h3_three_encoder_teacher_cosine_v1",
+  "metric": "same-teacher text-conditioning cosine similarity",
+  "definition": "Mean cosine similarity between candidate and teacher text-conditioning vectors in the original three-encoder comparison contract.",
+  "reference": {
+    "id": "official_nvfp4",
+    "label": "Official Qwen3-VL-32B NVFP4/AWQ reference",
+    "cosine_similarity": 1.0,
+    "note": "Identity/reference baseline; not a claim of visual equivalence."
+  },
+  "candidates": [
+    {
+      "id": "recovered_8b",
+      "label": "Recovered Qwen3-VL-8B + ARA + 4096-to-5120 adapter",
+      "cosine_similarity": 0.938678461010568,
+      "scope": "Text-only conditioning; within trained recovery scope."
+    },
+    {
+      "id": "pruned24_balanced_ara",
+      "label": "Physical pruned-24 Qwen3-VL-32B-derived INT8 ConvRot + balanced ARA",
+      "cosine_similarity": 0.9404705529707683,
+      "scope": "Text-only conditioning; within trained pruning scope."
+    }
+  ],
+  "interpretation": "These are conditioning-similarity diagnostics, not visual-quality, prompt-adherence, or video-equivalence scores.",
+  "source_contract": "Original three-encoder comparison contract, seed 861607, matched text-conditioning evaluation."
+}