fix: Report and retry media failures for every camera in a grid (#2658)

- Closes: #2637
 - Related: #2099

tests/browser/mounted-card.ts

@@ -607,10 +607,31 @@ export class MountedCard {
     control.click();
   }
 
+  /**
+   * Click the control that steps a carousel one item along.
+   *
+   * These carry the name of whatever they move to rather than a name of their
+   * own, which several other controls also carry, so they are reached by the
+   * side they sit on instead. Which side moves forward depends on the reading
+   * direction of the page, exactly as it does for the user.
+   */
+  public async clickNextPreviousControl(side: 'left' | 'right'): Promise<void> {
+    const control = await this.waitForRender(
+      () => deepQuery<HTMLElement>(this.card, `ha-icon-button.controls.${side}`),
+      `the ${side} carousel control`,
+    );
+
+    await clickElement(control);
+  }
+
   private async _findControl(name: string): Promise<HTMLElement> {
     return await this.waitForRender(() => {
       const found = deepQueryAll(this.card, '*').find(
-        (element) => getControlName(element) === name,
+        (element) =>
+          getControlName(element) === name &&
+          // A control the user can press occupies space. An element that only
+          // wraps one can carry the same name while having no box of its own.
+          !!element.getBoundingClientRect().width,
       );
       return found instanceof HTMLElement ? found : null;
     }, `a control named ${name}`);

tests/browser/test-utils.ts

@@ -90,7 +90,7 @@ export const createUnansweredMediaURL = (): string => createMediaURL([]);
  */
 export const createStallingMediaURL = (): string => createMediaURL([HTTP_OK]);
 
-export interface StillCameraHASSOptions {
+export interface CameraHASSOptions {
   // Camera entities beyond the default one.
   cameras?: string[];
 
@@ -105,7 +105,7 @@ export interface StillCameraHASSOptions {
  * A Home Assistant holding the cameras a card is about to be given, which is
  * the minimum any browser test needs before it can mount anything.
  */
-export const createStillCameraHASS = (options?: StillCameraHASSOptions): FakeHASS => {
+export const createCameraHASS = (options?: CameraHASSOptions): FakeHASS => {
   const cameras = [STILL_CAMERA_ENTITY, ...(options?.cameras ?? [])];
 
   return new FakeHASS({