refactor(lib): consolidate generic infra into src/lib

Move domain-agnostic, feature-free helpers out of the flat utils/ and store/
roots into src/lib/ (plan M4, §3 lib/ layer):
- lib/format/: formatBytes, formatClockTime, formatDuration, formatHumanDuration,
  relativeTime (pure format/date/byte/clock helpers)
- lib/i18n.ts: i18next bootstrap (global app infra)
- lib/util/: sanitizeHtml, platform, dedupeById, safeStorage (pure helpers +
  the zustand storage adapter)

playbackScheduleFormat stays in utils/format (runtime usePlayerStore dep =
audio-core coupling, not generic). formatClockTime keeps a type-only
@/store/authStoreTypes import (erased, no runtime inversion — accepted per the
deviceSync precedent).

Pure move via deep @/lib/* specifiers (no barrel → no mock-collapse surface).
tsc 0, lint 0/0, full suite 319 files / 2353 tests green.

Tooling note: lib_move.py regex extended to also rewrite side-effect imports
(import './i18n') and vi.importActual paths — both were silent gaps.

src/features/nowPlaying/components/AlbumCard.tsx

@@ -3,7 +3,7 @@ import { useTranslation } from 'react-i18next';
 import { Disc3, ExternalLink, Star } from 'lucide-react';
 import type { SubsonicAlbum, SubsonicSong } from '@/lib/api/subsonicTypes';
 import { formatTotalDuration } from '@/utils/componentHelpers/nowPlayingHelpers';
-import { formatTrackTime } from '@/utils/format/formatDuration';
+import { formatTrackTime } from '@/lib/format/formatDuration';
 
 interface AlbumCardProps {
   album: SubsonicAlbum | null;

src/features/nowPlaying/components/Hero.tsx

@@ -6,7 +6,7 @@ import type { CoverArtRef } from '@/cover/types';
 import type { ArtistStats, TrackStats } from '@/music-network';
 import type { SubsonicOpenArtistRef } from '@/lib/api/subsonicTypes';
 import { OpenArtistRefInline } from '@/features/artist';
-import { formatTrackTime } from '@/utils/format/formatDuration';
+import { formatTrackTime } from '@/lib/format/formatDuration';
 import { useEnrichmentPrimaryLabel } from '@/hooks/useEnrichmentPrimaryLabel';
 import { useEnrichmentPrimaryIcon } from '@/hooks/useEnrichmentPrimaryIcon';
 import { renderPresetIcon } from '@/components/settings/musicNetwork/presetIcon';

src/features/nowPlaying/components/RadioView.tsx

@@ -3,7 +3,7 @@ import { useTranslation } from 'react-i18next';
 import { Cast, Clock, Radio, SkipForward, Users } from 'lucide-react';
 import type { useRadioMetadata } from '@/features/radio';
 import { usePlayerStore } from '@/store/playerStore';
-import { formatTrackTime } from '@/utils/format/formatDuration';
+import { formatTrackTime } from '@/lib/format/formatDuration';
 
 type NonNullStoreField<K extends keyof ReturnType<typeof usePlayerStore.getState>> =
   NonNullable<ReturnType<typeof usePlayerStore.getState>[K]>;

src/features/nowPlaying/components/TopSongsCard.tsx

@@ -2,7 +2,7 @@ import React, { memo } from 'react';
 import { useTranslation } from 'react-i18next';
 import { ExternalLink, Play, TrendingUp } from 'lucide-react';
 import type { SubsonicSong } from '@/lib/api/subsonicTypes';
-import { formatTrackTime } from '@/utils/format/formatDuration';
+import { formatTrackTime } from '@/lib/format/formatDuration';
 
 interface TopSongsCardProps {
   artistName: string;