Move executable requests, nonces, deadlines, queued installs and retry timers into WidgetUpdateController. Keep configuration persistence and notification delivery in main.qml. Preserve forced checks at enabled startup and existing UpdateLogic decisions.

Development documentation and catalog source references updated; no user-visible behavior, configuration, CLI, metadata, or parity scope changes. Verified strict make check, real updater process tests, and installation in an isolated Plasma runtime.