phsl / new-api

Fix inconsistent loading state behavior where search buttons in ChannelsTable,
RedemptionsTable, and UsersTable didn't display loading animation when tables
were loading data, unlike LogsTable which handled this correctly.

Changes:
- Fix ChannelsTable searchChannels function to properly manage loading state
  - Move setSearching(true) to function start and use try-finally pattern
  - Ensure loading state is set for both search and load operations
- Update search button loading prop in ChannelsTable: loading={searching} → loading={loading || searching}
- Update search button loading prop in RedemptionsTable: loading={searching} → loading={loading || searching}
- Update search button loading prop in UsersTable: loading={searching} → loading={loading || searching}

This ensures search buttons show loading state consistently when:
- Table is loading data (initial load, pagination, operations)
- Search operation is in progress

All table components now provide unified UX behavior matching LogsTable,
preventing duplicate clicks and clearly indicating system state to users.