test(e2e): sweep the binding names a spec calls

Four specs still called `library.Library.GetTracks` after #281 replaced
it, and the suite reported twenty failures across transport, bottom-bar
and reduced-motion specs — none of which mention the library list. A
binding call carries only a method id, so a stale name fails at runtime
in whichever spec happens to call it.

`binding-names.spec.ts` reads every spec and harness file, extracts the
names they pass as strings, and checks them against the map derived
from the generated bindings tree. It asserts first that it read
something: a sweep over an empty glob passes and proves nothing.

It immediately found a second thing: `play-count.spec.ts` asserted that
a play refetched no collection by matching a `GetAll` prefix, which
matches exactly one real name (`GetAllLibrariesWithTrackCounts`) — so
the assertion held whatever the app refetched. It names the four
collection bindings now.

e2e/specs/bottom-bar.spec.ts

@@ -1,4 +1,10 @@
-import { test, expect, callBinding, NO_QUEUE_SOURCE } from '../support/fixtures.js';
+import {
+  test,
+  expect,
+  callBinding,
+  libraryTracks,
+  NO_QUEUE_SOURCE,
+} from '../support/fixtures.js';
 import type { Page } from '@playwright/test';
 
 /**
@@ -39,15 +45,7 @@ const geometry = (app: Page) =>
 
 /** Something has to be playing before the transport draws a seek bar. */
 async function play(app: Page): Promise<void> {
-  const paths = await app.evaluate(async () => {
-    const tracks = (await window.__yjEvents.call(
-      'library.Library.GetTracks',
-      [0],
-      10_000,
-    )) as { FilePath: string }[];
-
-    return tracks.slice(0, 3).map((t) => t.FilePath);
-  });
+  const paths = (await libraryTracks(app)).slice(0, 3).map((t) => t.FilePath);
 
   await callBinding(app, 'queue.Queue.SetQueue', [
     paths,