Reject invalid Qwen logits and discard poisoned sessions

docs/issue105-invalid-logits/checks.json

@@ -0,0 +1,37 @@
+{
+  "mtplx_sampler_entry_matches_reference": [
+    "test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 521 filtered out; finished in 59.33s"
+  ],
+  "mtplx_sampler_fallback_matches_reference": [
+    "test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 520 filtered out; finished in 3.76s"
+  ],
+  "mtplx_sampler_resident_matches_reference": [
+    "test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 520 filtered out; finished in 11.51s"
+  ],
+  "mtplx_sampler_batched": [
+    "test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 520 filtered out; finished in 115.98s"
+  ],
+  "product_ar": {
+    "cases": 24,
+    "invalid": 18,
+    "legal_mask": 6,
+    "status": "passed"
+  },
+  "product_mtp": {
+    "cases": 32,
+    "invalid": 24,
+    "legal_mask": 8,
+    "status": "passed"
+  },
+  "completion": "Acceptance, source review and all four commit gates passed.",
+  "commit_gates": {
+    "fmt": "passed",
+    "clippy_all_targets_all_features": "passed",
+    "make_bundle": "passed; ad-hoc codesigned",
+    "cargo_test_all_features": "308 application tests passed, 214 ignored; two tools each 4 passed"
+  },
+  "invalid_rows_vs_pinned_oracle": "passed; exact census/error text and valid tokens; invalid lazy sentinel -1",
+  "mtplx_sampler_mixed_distributions_match_reference": "100 cases passed in default cargo test",
+  "approved_exception": "User approved rejection throughout Qwen MTP on 2026-10-04, including specialized paths where the pinned oracle still fabricates token 0.",
+  "batched_greedy": "passed: each of 4 rows in both positions beside a healthy neighbor, widths 64 and 4097"
+}