feat(dialogs): polished success + error modals replace bare snackbar/dialog

Add reusable SuccessDialogComponent (green check, gradient hero, pop-in
animation) and redesign ErrorDialogComponent to match (red exclamation,
clear title, centered OK). Wire edit-user submit flow to the new dialogs:
success defers navigation until the user confirms, errors surface the
backend message in the styled modal instead of a grey snackbar.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/shared/error-dialog/error-dialog.component.html

@@ -6,17 +6,19 @@
   file, You can obtain one at http://mozilla.org/MPL/2.0/.
 -->
 
-<h1 mat-dialog-title>{{ 'Error Log' | translate }}</h1>
-
-<div mat-dialog-content>
+<mat-dialog-content class="ed-content">
+  <div class="ed-icon">
+    <fa-icon icon="exclamation-circle"></fa-icon>
+  </div>
+  <h2 class="ed-title">We encountered an issue. Please try again.</h2>
   @if (!showAsCode) {
-    <p>{{ displayData }}</p>
+    <p class="ed-message">{{ displayData }}</p>
   }
   @if (showAsCode) {
-    <span [innerHTML]="sanitizedData"></span>
+    <div class="ed-code" [innerHTML]="sanitizedData"></div>
   }
-</div>
+</mat-dialog-content>
 
-<mat-dialog-actions align="left">
-  <button mat-raised-button mat-dialog-close>{{ 'Cancel' | translate }}</button>
+<mat-dialog-actions align="center" class="ed-actions">
+  <button mat-flat-button color="warn" mat-dialog-close>OK</button>
 </mat-dialog-actions>