test(player): answer the commands the tap-surface tests actually render

VideoPlayer.tapSurface.test.ts deliberately does not mock $lib/api/bindings — it
renders the real component against the real bindings, which bottom out in the
globally mocked `invoke`. That mock resolves `undefined` for every command, so
any command whose result is *rendered* blows up: the quality picker assigns the
result straight to state and the template then reads `streamingQualities.length`,
which throws on undefined.

It threw asynchronously, outside any test, so the suite reported 4 unhandled
errors while every test still passed — the state vitest warns "might cause false
positive tests". Answering the two rendered commands removes them.

Authored in the main checkout; brought in here and verified: 83 files, 1009
tests, and the unhandled-error count drops from 4 to 0.

src/lib/components/player/VideoPlayer.tapSurface.test.ts

@@ -32,6 +32,7 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
 import { render } from "@testing-library/svelte";
 import { tick } from "svelte";
+import { invoke } from "@tauri-apps/api/core";
 import VideoPlayer from "./VideoPlayer.svelte";
 import { SEEK_FORWARD_SECONDS } from "./tapGestures";
 
@@ -128,6 +129,23 @@ function renderPlayer() {
 describe("VideoPlayer tap surface (real component)", () => {
   beforeEach(() => {
     vi.clearAllMocks();
+    // This file deliberately does NOT mock `$lib/api/bindings` — it renders the
+    // real component against the real bindings, which bottom out in the globally
+    // mocked `invoke`. That mock resolves `undefined` for every command, so the
+    // commands whose results are *rendered* have to be answered here: the
+    // quality picker assigns the result straight to state and then does
+    // `streamingQualities.length` in the template, which throws (asynchronously,
+    // outside any test) on undefined and fails the run with an unhandled error.
+    vi.mocked(invoke).mockImplementation(async (cmd: string) => {
+      switch (cmd) {
+        case "player_get_streaming_qualities":
+          return [];
+        case "player_get_video_settings":
+          return { streamingQuality: "original" };
+        default:
+          return undefined;
+      }
+    });
   });
 
   it("a single tap on the video toggles play/pause exactly once", async () => {