Improved Data Lookups for Theme Developers

Theme developers get stronger lookup tools, including all_* lookups and improved relationship lookups. This release also disables client sync paths that are no longer appropriate and tunes production data access.

Cleaner theme code

Themes can resolve content relationships, people, and programme structures directly, without hand-written API glue for every relationship. Pages that pull from multiple content types need fewer workarounds.

Production data access

Client sync paths that do not belong in production have been disabled. Production data access now reflects the patterns that are safe and correct for visitor-facing pages.