Rich text annotation types exported; pagination helpers…

Rich text annotation types are now exported (#740)
- Adds ApiColor, RichTextItemResponseCommon, and a new AnnotationResponse alias (the type of RichTextItemResponse.annotations) to the package entrypoint. Fixes #689; thanks @KingJing1.
- If you validate or construct rich text annotations: import these types directly instead of deriving them from RichTextItemResponse with indexed-access types.
Pagination helpers accept endpoint methods again under strictNullChecks (#744)
- v5.23.0 widened endpoint params to start_cursor?: string | null, but the PaginatedArgs constraint used by iteratePaginatedAPI / collectPaginatedAPI still only allowed string — so passing methods like client.dataSources.query to the helpers stopped compiling, with a misleading "property missing in type PaginatedArgs" error. Types-only fix (the runtime already handled null cursors), plus a regression test that compiles a real endpoint method against the helpers so this can't silently regress again. Fixes #743; thanks @nakanoasaservice.
- If the pagination helpers broke for you on v5.23.0, this is the fix — no code changes needed on your side.
Doc-comment fix: updateDataSource icon / in_trash descriptions now reference data sources (#745)
- Generated documentation strings only; no type or runtime changes.
Bump version to v5.23.1 (#746)

Rich text annotation types exported; pagination helpers fixed under strictNullChecks