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/hooks/tauriBridge/useCliBridge.ts

@@ -10,7 +10,7 @@ import { shuffleArray } from '../../utils/playback/shuffleArray';
 import { songToTrack } from '../../utils/playback/songToTrack';
 import { showToast } from '../../utils/ui/toast';
 import { switchActiveServer } from '../../utils/server/switchActiveServer';
-import i18n from '../../i18n';
+import i18n from '@/lib/i18n';
 import { usePlayerStore } from '../../store/playerStore';
 import { useAuthStore } from '../../store/authStore';
 import { executeCliPlayerCommand } from '../../config/shortcutActions';

src/hooks/useAppUpdater.ts

@@ -4,7 +4,7 @@ import { dirname } from '@tauri-apps/api/path';
 import { invoke } from '@tauri-apps/api/core';
 import { useTranslation } from 'react-i18next';
 import { version as currentVersion } from '../../package.json';
-import { IS_LINUX, IS_MACOS, IS_WINDOWS } from '../utils/platform';
+import { IS_LINUX, IS_MACOS, IS_WINDOWS } from '@/lib/util/platform';
 import { SKIP_KEY, isNewer, isWithinModerationWindow, pickAsset, type ReleaseData, type DlState } from '../utils/componentHelpers/appUpdaterHelpers';
 
 /** All update-modal state, the GitHub release probe and the download/relaunch

src/hooks/useAudioDevicesProbe.ts

@@ -3,7 +3,7 @@ import { invoke } from '@tauri-apps/api/core';
 import { listen } from '@tauri-apps/api/event';
 import type { TFunction } from 'i18next';
 import { useAuthStore } from '../store/authStore';
-import { IS_MACOS } from '../utils/platform';
+import { IS_MACOS } from '@/lib/util/platform';
 import { sortAudioDeviceIds } from '../utils/audio/audioDeviceLabels';
 import { showToast } from '../utils/ui/toast';
 

src/hooks/usePlatformShellSetup.ts

@@ -2,7 +2,7 @@ import { useEffect, useState } from 'react';
 import { invoke } from '@tauri-apps/api/core';
 import { useAuthStore } from '../store/authStore';
 import type { LinuxWaylandTextRenderProfile } from '../store/authStoreTypes';
-import { IS_LINUX, IS_MACOS, IS_WINDOWS } from '../utils/platform';
+import { IS_LINUX, IS_MACOS, IS_WINDOWS } from '@/lib/util/platform';
 
 /**
  * One-shot platform + window-shell configuration. Reads tiling-WM state,

src/hooks/useThemeAnimationRisk.ts

@@ -1,6 +1,6 @@
 import { useEffect, useState } from 'react';
 import { invoke } from '@tauri-apps/api/core';
-import { IS_LINUX } from '../utils/platform';
+import { IS_LINUX } from '@/lib/util/platform';
 
 /**
  * Whether animated themes may raise CPU load on this setup — Linux with the