refactor(dedup): consolidate byte / sanitize / clock / album-duration helpers (Phase L, part 2) (#692)

Findings 5-8 of the dedup audit:

- F5 byte formatters: appUpdaterHelpers.fmtBytes + ZipDownloadOverlay
  .formatMB route through the existing formatBytes; a new formatMb
  (always-MB) backs playlistDetailHelpers.formatSize, AlbumHeader and
  the 4 inline DeviceSyncPreSyncModal expressions. SongInfoModal.format
  Size is intentionally left — it uses decimal (1e6) divisors, not 1024.
- F6 sanitizeHtml: extracted to utils/sanitizeHtml.ts; AlbumHeader,
  ComposerDetail and the (now-empty, deleted) artistDetailHelpers use it
  directly. nowPlayingHelpers keeps its own export but now delegates to
  the shared sanitiser and only adds its trailing-link strip on top.
- F7 album duration: BecauseYouLikeRail's formatAlbumDuration drops in
  favour of the shared formatHumanHoursMinutes. Behaviour note: total
  minutes now floor instead of round (<=1 min display difference,
  matches every other caller).
- F8 clock time: extracted to utils/format/formatClockTime.ts;
  PlaybackDelayModal + QueueHeader use it (toLocaleTimeString and
  Intl.DateTimeFormat produced identical output).

Behaviour preserved except the two explicitly noted divergences (F7
round->floor; F5 appUpdater/Zip now show GB above 1 GB instead of a
large MB number).

src/components/AppUpdater.tsx

@@ -3,7 +3,7 @@ import { open } from '@tauri-apps/plugin-shell';
 import { ArrowUpCircle, CheckCircle2, ChevronDown, Download, FolderOpen, RefreshCw, ShieldCheck, X } from 'lucide-react';
 import { useTranslation } from 'react-i18next';
 import { version as currentVersion } from '../../package.json';
-import { fmtBytes } from '../utils/componentHelpers/appUpdaterHelpers';
+import { formatBytes } from '../utils/format/formatBytes';
 import { useAppUpdater } from '../hooks/useAppUpdater';
 import Changelog from './appUpdater/Changelog';
 
@@ -112,8 +112,8 @@ export default function AppUpdater() {
                   </div>
                   <span className="app-updater-pct">{pct}%</span>
                   <span className="update-modal-dl-bytes">
-                    {fmtBytes(dlProgress.bytes)}
-                    {dlProgress.total > 0 && ` / ${fmtBytes(dlProgress.total)}`}
+                    {formatBytes(dlProgress.bytes)}
+                    {dlProgress.total > 0 && ` / ${formatBytes(dlProgress.total)}`}
                   </span>
                 </div>
               )}
@@ -139,7 +139,7 @@ export default function AppUpdater() {
               {dlState === 'idle' && (
                 <div className="update-modal-asset">
                   <span className="update-modal-asset-name">{asset.name}</span>
-                  <span className="update-modal-asset-size">{fmtBytes(asset.size)}</span>
+                  <span className="update-modal-asset-size">{formatBytes(asset.size)}</span>
                 </div>
               )}
               {dlState === 'downloading' && (
@@ -149,8 +149,8 @@ export default function AppUpdater() {
                   </div>
                   <span className="app-updater-pct">{pct}%</span>
                   <span className="update-modal-dl-bytes">
-                    {fmtBytes(dlProgress.bytes)}
-                    {dlProgress.total > 0 && ` / ${fmtBytes(dlProgress.total)}`}
+                    {formatBytes(dlProgress.bytes)}
+                    {dlProgress.total > 0 && ` / ${formatBytes(dlProgress.total)}`}
                   </span>
                 </div>
               )}