Enhance dashboard filtering and runner manager administration with i18n updates

[LoicBonavent]

Summary

This PR improves dashboard filtering behavior, strengthens runner manager administration and task routing, and updates translation catalogs.

What changed

• Added support for dashboard filters using slugs, numeric IDs, and comma-separated query values.
• Improved filter synchronization between URL parameters, session storage, dashboard chips, and the category aside.
• Added a clear category filter action in the aside and kept UI state aligned with current query params.
• Hardened dashboard refresh JavaScript with defensive checks for missing globals and DOM elements.
• Added an is_active flag on runner managers to enable/disable managers without deleting configuration.
• Updated task dispatching and background processing to use active runner managers only.
• Kept tasks in pending state when no active runner manager is available for retry later.
• Improved runner admin UX with status badges and direct links to remote runner administration.
• Enhanced remote thumbnail import to support multiple generated thumbnails and avoid duplicate attachment.
• Added/updated tests for category CSV filtering, ID/CSV filters, runner admin UI behavior, and inactive-manager exclusion.
• Updated French translation catalogs.

Impact

• More robust and predictable dashboard filtering UX.
• Safer and clearer runner manager operations in admin and processing flows.
• Translation coverage updated for newly introduced admin and filter labels.