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/noise_removal.py

@@ -444,10 +444,12 @@ def main():
 
         try:
             import cv2
-        except ImportError:
+        except ImportError as e:
+            msg = str(e)
+            hint = "Fix with: apt-get install -y libgl1" if "libGL" in msg else "Install with: pip install opencv-python-headless"
             print(json.dumps({
                 "success": False,
-                "error": "OpenCV is not installed. Install with: pip install opencv-python-headless",
+                "error": f"Missing dependency: {msg}. {hint}",
             }))
             sys.exit(1)