Add Event Calendar feature with event occurrences service integration

Introduced a new Event Calendar component that displays scheduled events using the Heron.MudCalendar. Implemented IEventOccurrenceService to fetch event occurrences, and added mock data for initial testing. Updated navigation menu to include a link to the Event Calendar.

WebApp/Components/Features/EventCalendar/Index.razor

@@ -0,0 +1,63 @@
+@page "/event-calendar"
+@attribute [Authorize]
+@using WebApp.Components.Shared.Components
+@using WebApp.Models
+@using WebApp.Services
+@using Heron.MudCalendar
+@inject IEventOccurrenceService EventOccurrenceService
+
+<PageHeader Title="Event Calendar" Description="View competition schedules and event occurrences" />
+
+<MudPaper Elevation="2" Class="pa-6">
+    @if (_calendarItems == null)
+    {
+        <MudProgressLinear Indeterminate="true" />
+        <MudText>Loading calendar events...</MudText>
+    }
+    else
+    {
+        <MudCalendar T="CalendarEventItem" 
+                     Items="_calendarItems" 
+                     View="CalendarView.Day"
+                     CurrentDay=_calendarDate
+                     />
+    }
+</MudPaper>
+
+@code {
+    private List<CalendarEventItem>? _calendarItems;
+    private DateTime _calendarDate = DateTime.Today;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await LoadCalendarEvents();
+    }
+
+    private async Task LoadCalendarEvents()
+    {
+        var occurrences = await EventOccurrenceService.GetEventOccurrencesAsync();
+        _calendarItems = occurrences
+            .Select(occ => new CalendarEventItem(occ))
+            .ToList();
+
+        // Find the next date with events
+        _calendarDate = GetNextDateWithEvents();
+    }
+
+    private DateTime GetNextDateWithEvents()
+    {
+        if (_calendarItems == null || !_calendarItems.Any())
+        {
+            return DateTime.Today;
+        }
+
+        var today = DateTime.Today;
+        var nextEvent = _calendarItems
+            .Where(item => item.Start.Date >= today)
+            .OrderBy(item => item.Start)
+            .FirstOrDefault();
+
+        return nextEvent?.Start.Date ?? _calendarItems.OrderBy(item => item.Start).First().Start.Date;
+    }
+}
+

WebApp/Components/Shared/Layout/NavMenu.razor

@@ -17,6 +17,7 @@
             <MudNavLink Href="/teams/handout" Icon="@Icons.Material.Filled.Print">Handout</MudNavLink>
         </MudNavGroup>
         <MudNavLink Href="/meeting-schedule/" Icon="@AppIcons.Scheduler">Schedule</MudNavLink>
+        <MudNavLink Href="/event-calendar" Icon="@Icons.Material.Filled.CalendarMonth">Event Calendar</MudNavLink>
         <MudNavGroup Title="Team Building" Icon="@Icons.Material.Filled.GroupAdd" Expanded="true">
             <MudNavLink Href="/students/event-ranking" Icon="@AppIcons.EventRank">Event Ranking</MudNavLink>
             <MudNavLink Href="/teams/assignment" Icon="@AppIcons.TeamAssignment">Team Assignment</MudNavLink>

WebApp/Components/_Imports.razor

@@ -22,6 +22,7 @@
 @using WebApp.Components.Features.Events
 @using WebApp.Components.Features.Events.Components
 @using WebApp.Components.Features.MeetingSchedule
+@using WebApp.Components.Features.EventCalendar
 @using MudBlazor
 @using Core.Entities
 @using Data