fix(ai): surface actionable fix for libGL.so.1 missing on headless installs

Proxmox LXC and other headless Linux installs lack libgl1, causing
all AI tools to show a misleading "install opencv-python-headless"
error even though the pip package is already installed. Detect the
libGL ImportError and suggest `apt-get install -y libgl1` instead.

packages/ai/python/restore.py

@@ -16,7 +16,9 @@ try:
     import cv2
     from PIL import Image
 except ImportError as _e:
-    print(json.dumps({"error": f"Missing dependency: {_e}. Install opencv-python-headless, numpy, and Pillow."}))
+    _msg = str(_e)
+    _hint = "Fix with: apt-get install -y libgl1" if "libGL" in _msg else "Install opencv-python-headless, numpy, and Pillow."
+    print(json.dumps({"error": f"Missing dependency: {_msg}. {_hint}"}))
     sys.exit(1)