Clock and daytime were near-duplicates with different click semantics
(clock toggles between formats on left-click and opens the timezone
selector on right-click; daytime was non-pressable with a hover tooltip).
Standardize on clock, since it's the more capable of the two.
- Delete widgets/daytime.qml and its FirstPartyWidgets entry.
- Migrate shell-defaults.json, shell.qml's builtin fallback, Bar.qml's
fallback bar config, and the settings panel's builtin defaults so the
center anchor and center-section entry both reference "clock".
- Rename the daytimeSettings form to clockSettings and rephrase
"Tooltip format" → "Alternate format (click to toggle)" so the field
label matches clock's actual behavior.
- Update the gallery dropdown options and bar/README docs.