feat: Add timeline support for folder media (#2197)

- Closes #2106

src/components/timeline.ts

@@ -3,6 +3,7 @@ import { customElement, property } from 'lit/decorators.js';
 import { CameraManager } from '../camera-manager/manager';
 import { ViewItemManager } from '../card-controller/view/item-manager';
 import { ViewManagerEpoch } from '../card-controller/view/types';
+import { TimelineKey } from '../components-lib/timeline/types';
 import { TimelineConfig } from '../config/schema/timeline';
 import { CardWideConfig } from '../config/schema/types';
 import { HomeAssistant } from '../ha/types';
@@ -30,6 +31,16 @@ export class AdvancedCameraCardTimeline extends LitElement {
   @property({ attribute: false })
   public cardWideConfig?: CardWideConfig;
 
+  protected _getKeys(): TimelineKey[] {
+    const keys: TimelineKey[] = [];
+    for (const camera of this.cameraManager?.getStore().getCameraIDsWithCapability({
+      anyCapabilities: ['clips', 'snapshots', 'recordings'],
+    }) ?? []) {
+      keys.push({ type: 'camera', cameraID: camera });
+    }
+    return keys;
+  }
+
   protected render(): TemplateResult | void {
     if (!this.timelineConfig) {
       return html``;
@@ -43,9 +54,7 @@ export class AdvancedCameraCardTimeline extends LitElement {
         .thumbnailConfig=${this.timelineConfig.controls.thumbnails}
         .cameraManager=${this.cameraManager}
         .viewItemManager=${this.viewItemManager}
-        .cameraIDs=${this.cameraManager?.getStore().getCameraIDsWithCapability({
-          anyCapabilities: ['clips', 'snapshots', 'recordings'],
-        })}
+        .keys=${this._getKeys()}
         .cardWideConfig=${this.cardWideConfig}
         .itemClickAction=${this.timelineConfig.controls.thumbnails.mode === 'none'
           ? 'play'