Add failure-safe cluster image capture hook

Assistant: codex
Assistant-Model: gpt-6-astra
Assistant-Session: 01a06ecb-456a-71c2-b41e-0755d336e883

scripts/refresh_live_images.py

@@ -8,6 +8,7 @@ import hashlib
 import json
 import os
 from pathlib import Path
+import re
 import tempfile
 
 
@@ -17,7 +18,7 @@ def read_images(path: Path) -> set[str]:
         image = line.strip()
         if not image or image.startswith("#"):
             continue
-        if any(c.isspace() for c in image) or "/" not in image:
+        if not re.fullmatch(r"[A-Za-z0-9][A-Za-z0-9._:/@+-]*", image):
             raise ValueError("invalid image export")
         images.add(image)
     if not images: