Registers a new New Tab "Picture of the day" widget: the registry entry, the
three widget prefs, the component, and the customize-panel + about:preferences
toggles. It renders the "hidden picture" fallback state - a CSS sunrise gradient
with the context menu, an eye button, and a hover-revealed empty-state message.
The actual picture, localized description, set-as-wallpaper, and dismiss/restore
behaviors arrive with the Merino feed (Bug 2050976) and the follow-ups (Bug
2050975 / 2050973 / 2050972). For now the "Manage wallpaper" and "Hide today's
picture" context-menu items and the eye button are present but only emit
telemetry. The "small" size is deferred (Bug 2050970).
Telemetry uses the shared useWidgetTelemetry hook (generic widgets_* events; no
metrics.yaml change). Stacks on the strings patch (Bug 2050971 / D309659).
Differential Revision: https://phabricator.services.mozilla.com/D309727
Dre Grant
c79fab6b4a