fix: handle null bootstrap verification

install.sh

@@ -49,7 +49,10 @@ try:
 except Exception:
     sys.exit(0)
 
-notes = payload.get("verification", {}).get("notes", [])
+verification = payload.get("verification")
+notes = verification.get("notes", []) if isinstance(verification, dict) else []
+if not isinstance(notes, list):
+    notes = []
 for note in notes[:5]:
     print(f"[ERROR] {note}")
 
@@ -254,4 +257,6 @@ main() {
     echo ""
 }
 
-main "$@"
+if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
+    main "$@"
+fi

tests/test_codex_port_contracts.py

@@ -1,6 +1,8 @@
 import ast
 import json
 import re
+import subprocess
+import sys
 from pathlib import Path
 
 
@@ -196,6 +198,40 @@ def test_installers_use_bootstrap_json_output_file():
     assert "--json-output" in install_ps1
 
 
+def test_unix_installer_handles_null_verification_diagnostics():
+    payload = json.dumps(
+        {
+            "verification": None,
+            "steps": [
+                {
+                    "required": True,
+                    "ok": False,
+                    "group": "verification",
+                    "stderr": "verification unavailable",
+                }
+            ],
+        }
+    )
+    result = subprocess.run(
+        [
+            "bash",
+            "-c",
+            'source "$1"; PYTHON_BIN="$2"; print_bootstrap_diagnostics "$3"',
+            "bash",
+            str(ROOT / "install.sh"),
+            sys.executable,
+            payload,
+        ],
+        check=False,
+        capture_output=True,
+        text=True,
+    )
+
+    assert result.returncode == 0, result.stderr
+    assert "[ERROR] Failed bootstrap step: verification." in result.stdout
+    assert "[ERROR] verification unavailable" in result.stdout
+
+
 def test_api_readiness_matrix_covers_smoke_suite():
     smoke_text = (ROOT / "scripts" / "run_api_smoke_suite.py").read_text(encoding="utf-8")
     match = re.search(r"DEFAULT_SKILLS = (\[[\s\S]*?\])", smoke_text)