feat(TASK-017): adversary execution evidence + fail-closed routing

- parse extracts caller-declared verification_commands (schema + initial_state);
  never invents commands. parse gains fallback + state_updates capturing the
  failure string (TASK-016 fallback-capture warning stays silent).
- new run_checks script node (facts -> run_checks -> map_criteria, timeout
  3600): runs each declared command in the project dir (900s per-command
  timeout), records exec_results {cmd, exit, duration_s, tail~50}; 'none
  declared' / ENVIRONMENT markers instead of guessing or failing the node.
- check_criterion judges execution criteria against {{exec_results}} only:
  recorded green run = MET citing it, recorded failure = UNMET, markers =
  PARTIAL with an ENVIRONMENT note.
- fail-closed routing (R1/R2): parse/facts fallback -> pipeline_fault marker
  script -> verdict; holistic fallback -> verdict with holistic_failure
  captured. verdict.py: any PIPELINE-FAULT forces DIVERGES with the fault as
  complaint #1, per-criterion results still reported; report gains a
  'Verification runs:' section. Non-degraded semantics unchanged.
- R5 rust tests (python3-guarded, local cmd_available): verdict fault path,
  holistic-failure fault, CONFORMS regression, run_checks markers + recorded
  runs, crit_gate contract regression.

assets/agents/adversary/scripts/pipeline_fault.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+"""Fail-closed fault marker for the adversary graph.
+
+Reached ONLY via `fallback:` routes (parse, facts). Appends a machine-readable
+"PIPELINE-FAULT:" marker to `pipeline_faults` and continues to `verdict`,
+which turns any recorded fault into DIVERGES — the graph never dies without
+its sentinel, and a degraded run can never read as CONFORMS.
+
+Stage attribution: an llm-node failure writes an "LLM node …failed: <chain>"
+string into `parse_failure` via parse's `state_updates`; anything else means
+the deterministic facts (diff resolution) script failed, which leaves no
+failure text in state by design.
+"""
+
+import json
+import os
+
+MAX_DETAIL_CHARS = 500
+
+
+def load_state():
+    if path := os.environ.get("GRAPH_STATE_FILE"):
+        with open(path) as f:
+            return json.load(f)
+    return json.loads(os.environ.get("GRAPH_STATE", "{}"))
+
+
+def main():
+    state = load_state()
+    faults = [f for f in (state.get("pipeline_faults") or []) if isinstance(f, str)]
+    parse_failure = state.get("parse_failure")
+    detail = parse_failure.strip() if isinstance(parse_failure, str) else ""
+    if detail.startswith("LLM node"):
+        detail = detail.replace("\n", " ")
+        if len(detail) > MAX_DETAIL_CHARS:
+            detail = detail[: MAX_DETAIL_CHARS - 1] + "…"
+        faults.append(f"PIPELINE-FAULT: parse failed — cannot review: {detail}")
+    else:
+        faults.append(
+            "PIPELINE-FAULT: diff resolution failed — changed files and diff text "
+            "could not be resolved; criterion verification never ran"
+        )
+    print(json.dumps({"pipeline_faults": faults}))
+
+
+try:
+    main()
+except Exception as e:  # noqa: BLE001 — the fault marker itself must never crash
+    print(
+        json.dumps(
+            {
+                "pipeline_faults": [
+                    f"PIPELINE-FAULT: fault-marker script error: {e} — treat the "
+                    "run as degraded"
+                ]
+            }
+        )
+    )