fix(portals): address search back-button review (dialog guard, RTL-safe spacing)

- showBackButton now also checks !dialogRef, so a hypothetical dialog
  opened with isGlobalSearch:false from a workspace route can't show a
  back arrow that navigates the page behind the dialog (greptile).
- Replaced the fragile negative margin with a header-title-group flex
  wrapper (gap: 4px) that keeps the arrow and title together regardless
  of the outer gap or Material padding, and is RTL-safe (greptile).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

libs/portal/shared/ui/src/lib/components/search-layout/search-layout.component.html

@@ -7,17 +7,19 @@
             <div class="header sticky-header">
                 <div class="header-top">
                     <div class="header-left">
-                        @if (showBackButton()) {
-                            <button
-                                mat-icon-button
-                                class="header-back"
-                                [attr.aria-label]="'BACK' | translate"
-                                (click)="onBackClick()"
-                            >
-                                <mat-icon>arrow_back</mat-icon>
-                            </button>
-                        }
-                        <h2>{{ title() | translate }}</h2>
+                        <div class="header-title-group">
+                            @if (showBackButton()) {
+                                <button
+                                    mat-icon-button
+                                    class="header-back"
+                                    [attr.aria-label]="'BACK' | translate"
+                                    (click)="onBackClick()"
+                                >
+                                    <mat-icon>arrow_back</mat-icon>
+                                </button>
+                            }
+                            <h2>{{ title() | translate }}</h2>
+                        </div>
 
                         <!-- Filters slot -->
                         <div class="type-filters">

libs/portal/shared/ui/src/lib/components/search-layout/search-layout.component.scss

@@ -52,10 +52,16 @@
         flex: 1;
         flex-wrap: wrap;
 
+        // Keep the back arrow and title tightly grouped, independent of the
+        // wide gap between the title group and the filters (RTL-safe)
+        .header-title-group {
+            display: flex;
+            align-items: center;
+            gap: 4px;
+        }
+
         .header-back {
             flex-shrink: 0;
-            // Tighten the wide flex gap between the back arrow and the title
-            margin-right: -20px;
         }
 
         h2 {

libs/portal/xtream/feature/src/lib/search-results/search-results.component.ts

@@ -496,10 +496,13 @@ export class SearchResultsComponent implements AfterViewInit {
     /**
      * The in-portal search is a nested view (reached from the toolbar
      * search box or an actor page); the global search is a top-level
-     * sidebar destination, and the dialog has its own close button.
+     * sidebar destination, and the dialog has its own close button — a
+     * back arrow there would navigate the page behind the open dialog.
      */
     get showBackButton(): boolean {
-        return this.isWorkspaceLayout && !this.isGlobalSearch;
+        return (
+            this.isWorkspaceLayout && !this.isGlobalSearch && !this.dialogRef
+        );
     }
 
     get minSearchLength(): number {