phsl / new-api

1. Backend
   • `controller/channel.go`
     – Added pagination (`p`, `page_size`) support to `SearchChannels`.
     – Added independent `type` filter (keeps `type_counts` unaffected).
     – Returned `total`, `type_counts` to match `/api/channel/` response.

2. Frontend
   • `ChannelsTable.js`
     – `loadChannels` / `searchChannels` now pass `p`, `page_size`, `id_sort`, `type`, `status` correctly.
     – Pagination, page-size selector and type tabs work for both normal list and search mode.
     – Switch for “ID sort” calls proper API and keeps UI state in sync.
     – Removed unnecessary `normalize` helper; `getFormValues` back to concise form.

Result
• Search mode and normal listing now share identical pagination and filtering behavior.
• Type tabs show correct counts even after searching.
• “ID Sort” toggle no longer inverses actual behaviour.