implement calendar event display with day indicators and overlay

- Add ExpandedEvent type to shared package for recurring event instances
- Implement EventController and EventService with full CRUD operations
- Server-side recurring event expansion via recurrenceExpander
- Calendar grid shows orange dot indicator for days with events
- Tap on day opens modal overlay with EventCards
- EventCard component with Feather icons (calendar, clock, repeat, edit, trash)
- EventsStore with Zustand for client-side event state management
- Load events for visible grid range including adjacent month days
- Add textPrimary, borderPrimary, eventIndicator to theme
- Update test responses for multiple events on Saturdays

apps/client/src/Themes.tsx

@@ -9,8 +9,11 @@ type Theme = {
   rejectButton: string;
   disabledButton: string;
   buttonText: string;
+  textPrimary: string;
   textSecondary: string;
   textMuted: string;
+  eventIndicator: string;
+  borderPrimary: string;
 };
 
 const defaultLight: Theme = {
@@ -24,8 +27,11 @@ const defaultLight: Theme = {
   rejectButton: "#ef4444",
   disabledButton: "#ccc",
   buttonText: "#fff",
+  textPrimary: "#000000",
   textSecondary: "#666",
   textMuted: "#888",
+  eventIndicator: "#DE6C20",
+  borderPrimary: "#000000",
 };
 
 let currentTheme: Theme = defaultLight;