The model was inventing fake paths/URLs (e.g. files.oaiusercontent.com,
/home/ubuntu/navi-1/input_file_0.png) and calling image_view on them
when the user attached an image directly in chat — the image was
already in the multimodal context, but the tool description and lack
of a signal pushed the model to "load" it anyway.

- websocket.py: when a user message has inline images, append a brief
  note that they are already in context.
- image_view.py: soften the description — keep proactive use for paths
  and URLs the model genuinely cannot see, but tell it inline images
  don't need this tool.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>