- Derive selectedChannels from visibleChannels and clear selection on
filter change so bulk operations can never act on rows hidden by the
active filter (reachable via the 30s state poll under the on-air filter)
- Disable the per-row delete button while a mutation is in flight
- Correct the --pad-cell-x fallback (token resolves to 16px)
- Add tests: bulk renumber request body + selection clearing, and
selection reset across filter changes
Review: PR #124 findings 1, 2, 4, 8
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>