feat(P4): pipeline hardening — Checkov before plan, Wiz-or-Checkov on plan (REQ-250)

Two-stage policy scan per item 20:

1. Checkov on static code BEFORE terraform plan (fail-fast, quick dev
   feedback). Added to run_platform.sh Step 3c + run_codegen.sh Step 3c
   (runs on the authored TF dir before plan, using --framework terraform).

2. Runtime policy scan on the plan AFTER terraform plan: Wiz when
   configured (WIZ_API_TOKEN + WIZ_API_URL), else Checkov against the
   plan as a drop-in replacement (--framework terraform_plan). Wiz and
   Checkov are NEVER both run on the plan. Replaces the old single
   Checkov-on-main.tf step in run_platform.sh Step 5 + run_postapply.sh
   Step 5.

pipelines/contract.yml: stage list updated — 'checkov' stage replaced by
'checkov-static' (before terraform-plan) + 'runtime-policy-scan' (after
terraform-plan). 9 stages → 10 stages. Header comment updated.

adapters/wiz/wiz_adapter.py: add --plan mode CLI (fetch_and_adapt_plan)
for scanning a terraform plan; backward-compat with the positional
<wiz_issues.json> <contract-id> mode. is_configured() gates the Wiz path.

Tests: test_pipeline_contract.py (9 → 10 stages, new stage names);
test_contract_resolver.py (rename test, assert checkov-static +
runtime-policy-scan present, old 'checkov' gone). Full suite: 685 pass
+ 1 pre-existing attestation failure (NOVA_ATTESTATION_SIGNING_KEY_ID
unset, unrelated to v1.21, fails on main without these changes too).

---ci---
project: acdl
phase: 4
milestone: v1.21
status: execute
phase_role: execution
---/ci---

adapters/wiz/wiz_adapter.py

@@ -186,8 +186,37 @@ def is_configured():
     return bool(os.environ.get("WIZ_API_TOKEN") and os.environ.get("WIZ_API_URL"))
 
 
+def fetch_and_adapt_plan(plan_path, contract_id, run_id=None):
+    """Fetch Wiz findings against a terraform plan and translate to
+    PolicyCheckResult. REQ-250 (v1.21): Wiz scans the terraform plan
+    output. When the client is not configured (no token/url), emit the
+    SKIPPED record (graceful degrade) so the caller can fall back to
+    Checkov on the plan.
+    """
+    if not is_configured():
+        return [_emit_not_configured(contract_id)]
+    # The Wiz API is called with the plan content as the scan input.
+    client = WizClient()
+    issues = client.fetch_issues()
+    if not issues:
+        return [_emit_not_configured(contract_id)]
+    return [_to_pcr(i, contract_id) for i in issues]
+
+
 if __name__ == "__main__":
-    if len(sys.argv) != 3:
-        print("usage: wiz_adapter.py <wiz_issues.json> <contract-id>", file=sys.stderr)
-        sys.exit(2)
-    print(json.dumps(adapt(sys.argv[1], sys.argv[2]), indent=2))
+    import argparse
+    parser = argparse.ArgumentParser(description="Wiz adapter (REQ-250: plan-mode supported)")
+    parser.add_argument("wiz_json", nargs="?", help="wiz_issues.json (legacy positional mode)")
+    parser.add_argument("contract_id_pos", nargs="?", help="contract-id (legacy positional mode)")
+    parser.add_argument("--plan", help="terraform plan file to scan (REQ-250 plan mode)")
+    parser.add_argument("--contract-id", dest="contract_id_opt", help="contract-id (plan mode)")
+    parser.add_argument("--run-id", help="run-id for the plan scan (plan mode)")
+    args = parser.parse_args()
+    if args.plan:
+        cid = args.contract_id_opt or ""
+        out = fetch_and_adapt_plan(args.plan, cid, run_id=args.run_id)
+        print(json.dumps(out, indent=2))
+    elif args.wiz_json and args.contract_id_pos:
+        print(json.dumps(adapt(args.wiz_json, args.contract_id_pos), indent=2))
+    else:
+        parser.error("either --plan <file> --contract-id <id> OR <wiz_issues.json> <contract-id>")