feat(stalker): add back button in details view

Add clearSelectedItem() to the stalker store to reset selected item
state (selectedVodId, selectedSerialId, selectedItvId, selectedItem).
This centralizes clearing logic and avoids manual nulling elsewhere.
Introduce goBackToList() in the container component to use the new
store method when navigating back from item details. Update the
template to conditionally show the back button when a selected item
exists, and ensure category title rendering and the disabled category
button behave correctly with the new conditional structure.
These changes simplify state management for returning from detail
views and make the template logic clearer and less error-prone.

apps/web/src/app/stalker/stalker-main-container.component.html

@@ -90,19 +90,17 @@
 <div class="main-content">
     <div class="content-header">
         <h2>
-            @if (
-                currentLayout === 'vod-details' ||
-                currentLayout === 'serial-details'
-            ) {
-                <button mat-icon-button (click)="historyBack()">
+            @if (stalkerStore.selectedItem()) {
+                <button mat-icon-button (click)="goBackToList()">
                     <mat-icon>chevron_left</mat-icon>
                 </button>
+            } @else if (!isItvCategorySelected) {
+                <button mat-icon-button disabled>
+                    <mat-icon>category</mat-icon>
+                </button>
             }
 
             @if (!isItvCategorySelected) {
-                <button mat-icon-button disabled>
-                    <mat-icon>category</mat-icon>
-                </button>
                 {{ selectedCategoryTitle() }}
             }
 

apps/web/src/app/stalker/stalker-main-container.component.ts

@@ -236,4 +236,8 @@ export class StalkerMainContainerComponent {
     backToCategories() {
         this.stalkerStore.setSelectedCategory(null);
     }
+
+    goBackToList() {
+        this.stalkerStore.clearSelectedItem();
+    }
 }

apps/web/src/app/stalker/stalker.store.ts

@@ -332,6 +332,14 @@ export const StalkerStore = signalStore(
                     selectedItem,
                 });
             },
+            clearSelectedItem() {
+                patchState(store, {
+                    selectedVodId: undefined,
+                    selectedSerialId: undefined,
+                    selectedItvId: undefined,
+                    selectedItem: undefined,
+                });
+            },
             setCategories(type: 'vod' | 'series' | 'itv', categories: any[]) {
                 if (type === 'vod') {
                     patchState(store, { vodCategories: categories });