remove subdomain feature

frontend/src/app/dashboard/create-site-dialog/create-site-dialog.ts

@@ -21,15 +21,6 @@ import { SiteService } from '../../core/services/site.service';
           <mat-error>Name is required</mat-error>
         </mat-form-field>
 
-        <mat-form-field appearance="outline" class="w-full">
-          <mat-label>Subdomain</mat-label>
-          <input matInput formControlName="subdomain" placeholder="my-site" />
-          <mat-error *ngIf="form.get('subdomain')?.hasError('required')">Subdomain is required</mat-error>
-          <mat-error *ngIf="form.get('subdomain')?.hasError('pattern')">
-            Lowercase letters, numbers, and hyphens only
-          </mat-error>
-        </mat-form-field>
-
         <mat-form-field appearance="outline" class="w-full">
           <mat-label>Description (optional)</mat-label>
           <textarea matInput formControlName="description" rows="3" placeholder="What's your site about?"></textarea>
@@ -51,7 +42,6 @@ export class CreateSiteDialog {
 
   form = this.fb.group({
     name: ['', Validators.required],
-    subdomain: ['', [Validators.pattern(/^[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?$/)]],
     description: [''],
   });
   loading = false;