Merge release/v2.11.0 into feat/agenda-range-limit

Integrate #3/#5/#6 (week-start, time-format, hour-lines) into the agenda
range branch. SettingsViewModel folds all five view prefs into one combine;
WidgetData keeps the range-based window and adds the resolved is24Hour.

Also, in the same Appearance section:
- regroup the rows into four titled-by-spacing groups (theme & colour /
  calendar layout / timeline display / agenda) instead of one long card.
- add an explanatory description line under the title of each agenda-range
  picker (PickerDescription).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/src/main/res/values/strings.xml

@@ -269,10 +269,16 @@
     <string name="settings_dynamic_color_unavailable">Requires Android 12 or newer</string>
     <string name="settings_week_start">Week starts on</string>
     <string name="settings_week_start_auto">Automatic</string>
-    <string name="settings_week_start_monday">Monday</string>
-    <string name="settings_week_start_sunday">Sunday</string>
+    <string name="settings_time_format">Time format</string>
+    <string name="settings_time_format_auto">Automatic</string>
+    <string name="settings_time_format_12h">12-hour (2:00 PM)</string>
+    <string name="settings_time_format_24h">24-hour (14:00)</string>
+    <string name="settings_hour_lines">Hour lines</string>
+    <string name="settings_hour_lines_summary">Show a separator line at each hour in week and day view</string>
     <string name="settings_agenda_range">Agenda range</string>
+    <string name="settings_agenda_range_hint">How far ahead the Agenda screen lists events.</string>
     <string name="settings_agenda_widget_range">Agenda widget range</string>
+    <string name="settings_agenda_widget_range_hint">How far ahead the agenda home-screen widget lists events.</string>
     <string name="agenda_range_day">Today</string>
     <string name="agenda_range_this_week">This week</string>
     <string name="agenda_range_this_month">This month</string>