ClawHub installs fail for ambiguous slugs because ownerHandle is not forwarded

Summary

Installing a ClawHub skill whose slug is shared by multiple publishers fails in the OpenFang dashboard. The daemon is healthy; the UI reports a misleading "daemon unavailable" message after the install endpoint returns 502.

Reproduction

1. Start OpenFang 0.6.9 with the dashboard enabled.
2. Open Skills -> ClawHub.
3. Select weather and click Install.

Actual result

The server log shows:

Downloading skill from ClawHub slug="weather"
ClawHub install failed: Network error: ClawHub download returned 409 Conflict
POST /api/clawhub/install status=502

The upstream endpoint responds:

Ambiguous skill slug "weather". Multiple publishers use this slug. Retry with ownerHandle, for example: /api/v1/download?slug=weather&ownerHandle=<owner>.

ClawHubClient::install_with_options currently calls /api/v1/download?slug=<slug> without forwarding an owner/publisher identifier.

Expected result

The dashboard should pass the selected skill's owner handle to the download endpoint, so duplicate slugs can be installed. If the API response is still an error, it should be shown to the user instead of being presented as a daemon availability problem.

Notes

Browsing the ClawHub catalog and the rest of the daemon work normally. The issue is specific to installing duplicate slugs through the ClawHub integration.