Add a new Rerank tab to the playground that lets users test /v1/rerank
endpoints. Supports a visual table editor and a JSON editor mode that
stay in sync when toggling between them.
- add rerankApi.ts with typed wrapper for /v1/rerank
- add RerankInterface.svelte with query input, sortable document table,
color-coded scores, auto-add row, cancel/clear, and token usage
- add rerankLoading store to playgroundActivity derived store
- register Rerank tab in Playground.svelte
Updates #481
Benson Wong