Add schedule sync and schedule-aware playback

src/proclamation_options_page.h

@@ -28,14 +28,14 @@ public:
 
 private:
     struct FlatItem {
-        enum class Type { Category, Group, Proclamation };
+        enum class Type { ScheduleToggle, Category, Group, Proclamation };
 
         Type type = Type::Proclamation;
-        std::string id;         // category id, group id, or proclamation id
+        std::string id;         // category id, group id, proclamation id, or "schedule"
         std::string label;      // display text
         int depth = 0;          // 0 = category / default, 1 = group, 2 = proclamation
         bool expanded = false;  // categories and groups only
-        bool selected = false;  // proclamations only
+        bool selected = false;  // proclamations and the schedule toggle
         bool isDefault = false; // the always-on top-level proclamation
     };