Describes which object types are always-flat (never nested in URL) for
ALL operations, vs event sub-objects which use nested paths for mutations
but flat paths for all reads (GET, list, search, delete).
Always-flat objects:
- Core: account, activity_log, address, contact, hosted_file, organization,
page, person, site, user
- Other: archive, event, journal, post
Event sub-objects (event_badge, event_session, etc.) use nested
create_nested_obj_v3 / update_nested_obj_v3 for POST/PATCH, but flat
paths for everything else.
Includes Playwright mock URL patterns for each operation type.
