refactor(player): E.42 — migrate playerStore re-exports to direct imports (#607)

Migrates ~74 call sites away from the playerStore re-export shims that
were kept during M0–E.41 to avoid touching 30+ imports per PR. Now
that the bigger refactor work is done, each helper goes back to its
real home:

- `initAudioListeners`, `installQueueUndoHotkey`, `flushPlayQueuePosition`
  → from their own store modules
- `getPlaybackProgressSnapshot`, `subscribePlaybackProgress`,
  `PlaybackProgressSnapshot` → from `playbackProgress`
- `resolveReplayGainDb`, `shuffleArray`, `songToTrack`
  → from `utils/*`
- `_resetQueueUndoStacksForTest`, `consumePendingQueueListScrollTop`,
  `registerQueueListScrollTopReader` → from `queueUndo`
- `PlayerState`, `Track` types → from `playerStoreTypes`

Drops the corresponding 13 re-export stubs from `playerStore.ts` and
the now-unused imports. Also drops dead section banners + per-wrapper
comments above one-line action delegates. Trims one stale "(separate
PR)" note in `transportLightActions.ts` since that follow-up landed
in E.39.

`playerStore.ts`: 180 → 112 LOC (−68). Down from Phase E's starting
3732 LOC.

`bootstrap.test.ts` mock target updated from `../store/playerStore`
to `../store/queueUndoHotkey` to keep the spy reachable after the
import change.

src/app/bootstrap.test.ts

@@ -6,13 +6,14 @@
  * payload) and the failure-tolerant path (no throw when invoke or storage
  * misbehaves).
  */
+import { installQueueUndoHotkey } from '../store/queueUndoHotkey';
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 
 vi.mock('@tauri-apps/api/core', () => ({
   invoke: vi.fn(),
 }));
 
-vi.mock('../store/playerStore', () => ({
+vi.mock('../store/queueUndoHotkey', () => ({
   installQueueUndoHotkey: vi.fn(),
 }));
 
@@ -21,7 +22,6 @@ vi.mock('./windowKind', () => ({
 }));
 
 import { invoke } from '@tauri-apps/api/core';
-import { installQueueUndoHotkey } from '../store/playerStore';
 import { getWindowKind } from './windowKind';
 import {
   pushLoggingModeToBackend,