User-visible strings, doc comments and docs now say "Favorite" and
"color", matching the `pdfs favorite` command; UI_UX_PLAN.md §8 records
the choice. The changelog's 1.11.x and Unreleased entries said schema 30,
but V31 (`photos.resolved_at`) shipped in 1.11.0. Adds the missing
release links for 1.10.0 to 1.11.1.
Audit of every GUI page, the photo viewer, the tray and the backend
capabilities a sync UI needs. Lists found bugs, a glossary, a new
information architecture (Sync hub, Preferences dialog) and a phased
roadmap including pause/resume and conflict resolution.