Smoke-tested against a live server: Pin didn't work from the sidebar
context menu, Subscribe/Unsubscribe worked, Enable Embeds didn't.
- Sidebar document context menu still had the pre-pins.*-support
disabled Pin/Unsubscribe stubs from before that endpoint existed -
only the reader's menu got updated at the time. Wired up real Pin
(collection-scoped pins.list loaded once per CollectionDocumentsOutline,
not per row - avoids an N+1 call storm); left Unsubscribe disabled
there since subscriptions.list is per-document, with an accurate
comment pointing at the reader's menu instead.
- documentEmbeds confirmed not a real field - removed from
UpdateDocumentRequest entirely rather than leave a menu item that
silently no-ops.
- Subscribe, Viewer Insights, and Full Width are now real Toggle menu
items (checkmark reflects actual state) instead of static
action buttons. Viewer Insights state is inferred from whether
documents.insights succeeds/fails, since insightsEnabled isn't
readable back off Document - heuristic, flagged in code.