Claude Agent has no available models in Remote-SSH Chat view, but works in Agents Window on the same SSH host

Environment:
VS Code 1.133.0
Windows client
Remote-SSH → Linux x64
Copilot Pro

1. Open remote folder via Remote-SSH.
2. Open Chat view.
3. Select Claude agent.
4. UI reports no available models.

Remote Agent Host log:
[Claude] Models refreshed (merged). Count: 0

But Copilot provider on the same remote sees:
Claude Sonnet 4.6
Claude Sonnet 4.5
Claude Haiku 4.5

5. Open Agents Window.
6. Select the exact same SSH host and exact same folder.
7. Select Claude.
8. Claude Haiku/Sonnet models are available and Claude works.

Remote-SSH Agent Host additionally reports:
ENOPRO: No file system provider found for
vscode-remote://ssh-remote+...