Only show gallery back button in certain cases.

src/components/gallery.ts

@@ -129,6 +129,18 @@ export class FrigateCardGalleryCore extends LitElement {
     );
   }
 
+  /**
+   * Determine whether the back arrow should be displayed.
+   * @returns `true` if the back arrow should be displayed, `false` otherwise.
+   */
+  protected _showBackArrow(): boolean {
+    return (
+      !!this.view?.previous &&
+      !!this.view.previous.target &&
+      this.view.previous.view === this.view.view
+    );
+  }
+
   /**
    * Master render method.
    * @returns A rendered template.
@@ -158,7 +170,7 @@ export class FrigateCardGalleryCore extends LitElement {
     };
 
     return html` <ul class="mdc-image-list frigate-card-gallery">
-      ${this.view && this.view.previous
+      ${this._showBackArrow()
         ? html`<li class="mdc-image-list__item" style="${styleMap(itemStyle)}">
             <div class="mdc-image-list__image-aspect-container">
               <div class="mdc-image-list__image">

src/components/timeline.ts

@@ -1,4 +1,3 @@
-// TODO: Hover over an event should show something useful.
 // TODO: Periodically refetch events.
 // TODO: Editor support for timeline (incl. in views).
 // TODO: Make thumbnail controls optional (in all places that use thumbnails).