Effective config: editable badge in view mode, refresh on continue/stop after save failure

- Multi-value items: EditableAsButton=true so 'editable' badge is clickable in view
  mode and activates the field like other editable badges.
- Save modal: 'Continue editing' after ValidateFailed/ReloadFailed now discards
  session, refreshes config from disk, then re-enters edit mode so remove/UI
  work correctly.
- 'Stop editing' after ValidateFailed/ReloadFailed now triggers config refresh
  so the invalid value on disk is shown instead of stale UI.
- SaveFlow: HandleCloseAndEndEdit invokes OnSaveCompleted when in failed state;
  OnContinueEditing uses EventCallback.Factory.Create to fix method-group
  conversion warning.

src/DnsmasqWebUI/Components/EffectiveConfig/Modals/EffectiveConfigSaveModal.razor

@@ -153,7 +153,7 @@
                 @if ((SaveState == EffectiveConfigSaveFlow.SaveUiState.ReloadFailed || SaveState == EffectiveConfigSaveFlow.SaveUiState.ValidateFailed) && SaveResult?.BackupPath != null)
                 {
                     <button type="button" class="btn btn-primary" @onclick="() => Restore(SaveResult.BackupPath)"><i class="bi bi-arrow-counterclockwise me-1" aria-hidden="true"></i>Restore backup</button>
-                    <button type="button" class="btn btn-outline-warning" @onclick="Close"><i class="bi bi-pencil me-1" aria-hidden="true"></i>Continue editing</button>
+                    <button type="button" class="btn btn-outline-warning" @onclick="ContinueEditing"><i class="bi bi-pencil me-1" aria-hidden="true"></i>Continue editing</button>
                     <button type="button" class="btn btn-danger" @onclick="CloseAndEndEdit"><i class="bi bi-x-circle me-1" aria-hidden="true"></i>Stop editing</button>
                 }
                 else if (SaveState == EffectiveConfigSaveFlow.SaveUiState.RestoreFailed)
@@ -184,6 +184,7 @@
     [Parameter] public EffectiveConfigSaveResult? SaveResult { get; set; }
     [Parameter] public EffectiveConfigRestoreResult? RestoreResult { get; set; }
     [Parameter] public EventCallback OnClose { get; set; }
+    [Parameter] public EventCallback OnContinueEditing { get; set; }
     [Parameter] public EventCallback OnSave { get; set; }
     [Parameter] public EventCallback<string> OnRestore { get; set; }
     [Parameter] public EventCallback OnReverted { get; set; }
@@ -262,6 +263,12 @@
         await OnClose.InvokeAsync();
     }
 
+    private async Task ContinueEditing()
+    {
+        if (!AllowClose) return;
+        await OnContinueEditing.InvokeAsync();
+    }
+
     private async Task Save()
     {
         await OnSave.InvokeAsync();