fix: update Angular CLI version and refactor dialog component template

- Updated @angular/cli from version ~20.0.3 to ~20.3.6 in package.json.
- Refactored dialog.component.html to remove optional chaining from ngModel bindings for event properties.

theme/packages/main/package.json

@@ -46,7 +46,7 @@
   },
   "devDependencies": {
     "@angular/build": "^20.0.3",
-    "@angular/cli": "~20.0.3",
+    "@angular/cli": "~20.3.6",
     "@angular/compiler-cli": "^20.0.4",
     "@types/chance": "^1.1.6",
     "@types/date-fns": "^2.6.3",

theme/packages/main/src/app/pages/apps/fullcalendar/dialog.component.html

@@ -23,7 +23,7 @@
           <input
             matInput
             placeholder="Edit Title"
-            [(ngModel)]="data?.event.title"
+            [(ngModel)]="data.event.title"
           />
         </mat-form-field>
       </div>
@@ -34,7 +34,7 @@
             matInput
             placeholder="Change Color"
             type="color"
-            [(ngModel)]="data?.event.color.primary"
+            [(ngModel)]="data.event.color.primary"
           />
         </mat-form-field>
       </div>
@@ -46,7 +46,7 @@
             [matDatepicker]="startDateDP"
             placeholder="Start Date"
             name="startDate"
-            [(ngModel)]="data?.event.start"
+            [(ngModel)]="data.event.start"
           />
           <mat-datepicker-toggle
             matSuffix
@@ -63,7 +63,7 @@
             [matDatepicker]="endDateDP"
             placeholder="End Date"
             name="endDate"
-            [(ngModel)]="data?.event.end"
+            [(ngModel)]="data.event.end"
           />
           <mat-datepicker-toggle
             matSuffix