Add hosted-engine (jev-1.13.0) column: 90.2% overall, most format-stable (2.9-8.3% flips)

reports/fragility_jev.json

@@ -0,0 +1,23 @@
+{
+  "model": "jev-1.13.0",
+  "rows": 480,
+  "errors": 0,
+  "overall_accuracy": 0.902,
+  "baseline_accuracy": 0.95,
+  "by_order": {
+    "forward": 0.908,
+    "reversed": 0.896
+  },
+  "by_keys": {
+    "abstract": 0.867,
+    "q0": 0.967,
+    "q1": 0.833,
+    "semantic": 0.939
+  },
+  "flip_rate": {
+    "keys_semantic_vs_abstract": 0.083,
+    "order_forward_vs_reversed": 0.029,
+    "phrasing_p0_vs_p1": 0.037
+  },
+  "latency_ms_p50": 862.99
+}