refactor(utils): group utils/ files into topic folders (Phase L, part 1) (#689)

111 of 122 top-level src/utils/ files move into 16 topic folders (audio,
cache, cover, share, server, playback, playlist, deviceSync, waveform,
mix, format, export, changelog, ui, perf, componentHelpers). True
singletons with no cluster stay at the utils/ root.

Pure file-move: a path-aware codemod rewrote 539 relative-import
specifiers across 275 files; no logic touched. The hot-path coverage
gate list (.github/frontend-hot-path-files.txt) is updated to the new
paths for the 11 gated utils files — a mechanical consequence of the
move, not a CI change. tsc is green.

src/components/settings/AddServerForm.tsx

@@ -2,14 +2,14 @@ import React, { useEffect, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import { Eye, EyeOff } from 'lucide-react';
 import type { ServerProfile } from '../../store/authStoreTypes';
-import { showToast } from '../../utils/toast';
+import { showToast } from '../../utils/ui/toast';
 import {
   decodeServerMagicString,
   encodeServerMagicString,
   DECODED_PASSWORD_VISUAL_MASK,
   type ServerMagicPayload,
-} from '../../utils/serverMagicString';
-import { shortHostFromServerUrl } from '../../utils/serverDisplayName';
+} from '../../utils/server/serverMagicString';
+import { shortHostFromServerUrl } from '../../utils/server/serverDisplayName';
 
 export function AddServerForm({
   onSave,

src/components/settings/AudioTab.tsx

@@ -4,7 +4,7 @@ import { Music2, Sliders, Waves } from 'lucide-react';
 import { useAuthStore } from '../../store/authStore';
 import Equalizer from '../Equalizer';
 import SettingsSubSection from '../SettingsSubSection';
-import { effectiveLoudnessPreAnalysisAttenuationDb } from '../../utils/loudnessPreAnalysisSlider';
+import { effectiveLoudnessPreAnalysisAttenuationDb } from '../../utils/audio/loudnessPreAnalysisSlider';
 import { useAudioDevicesProbe } from '../../hooks/useAudioDevicesProbe';
 import { AudioOutputDeviceSection } from './audio/AudioOutputDeviceSection';
 import { NormalizationBlock } from './audio/NormalizationBlock';

src/components/settings/BackupSection.tsx

@@ -1,8 +1,8 @@
 import { useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import { Download, HardDrive, Upload } from 'lucide-react';
-import { exportBackup, importBackup } from '../../utils/backup';
-import { showToast } from '../../utils/toast';
+import { exportBackup, importBackup } from '../../utils/export/backup';
+import { showToast } from '../../utils/ui/toast';
 
 export function BackupSection() {
   const { t } = useTranslation();

src/components/settings/ServersTab.tsx

@@ -7,10 +7,10 @@ import { useAuthStore } from '../../store/authStore';
 import type { ServerProfile } from '../../store/authStoreTypes';
 import { pingWithCredentials, scheduleInstantMixProbeForServer } from '../../api/subsonic';
 import { useDragDrop } from '../../contexts/DragDropContext';
-import { type ServerMagicPayload } from '../../utils/serverMagicString';
-import { showAudiomuseNavidromeServerSetting } from '../../utils/subsonicServerIdentity';
-import { serverListDisplayLabel } from '../../utils/serverDisplayName';
-import { switchActiveServer } from '../../utils/switchActiveServer';
+import { type ServerMagicPayload } from '../../utils/server/serverMagicString';
+import { showAudiomuseNavidromeServerSetting } from '../../utils/server/subsonicServerIdentity';
+import { serverListDisplayLabel } from '../../utils/server/serverDisplayName';
+import { switchActiveServer } from '../../utils/server/switchActiveServer';
 import { AddServerForm } from './AddServerForm';
 import { ServerGripHandle } from './ServerGripHandle';
 

src/components/settings/SidebarCustomizer.tsx

@@ -6,7 +6,7 @@ import { useAuthStore } from '../../store/authStore';
 import { useSidebarStore, SidebarItemConfig } from '../../store/sidebarStore';
 import { useLuckyMixAvailable } from '../../hooks/useLuckyMixAvailable';
 import { ALL_NAV_ITEMS } from '../../config/navItems';
-import { applySidebarDropReorder } from '../../utils/sidebarNavReorder';
+import { applySidebarDropReorder } from '../../utils/componentHelpers/sidebarNavReorder';
 
 type DropTarget = { idx: number; before: boolean; section: 'library' | 'system' } | null;
 

src/components/settings/StorageTab.tsx

@@ -8,8 +8,8 @@ import { useHotCacheStore } from '../../store/hotCacheStore';
 import { useOfflineStore } from '../../store/offlineStore';
 import { usePlayerStore } from '../../store/playerStore';
 import { clearImageCache, getImageCacheSize } from '../../utils/imageCache';
-import { formatBytes, snapHotCacheMb } from '../../utils/formatBytes';
-import { showToast } from '../../utils/toast';
+import { formatBytes, snapHotCacheMb } from '../../utils/format/formatBytes';
+import { showToast } from '../../utils/ui/toast';
 import SettingsSubSection from '../SettingsSubSection';
 
 export function StorageTab() {

src/components/settings/SystemTab.tsx

@@ -9,7 +9,7 @@ import i18n from '../../i18n';
 import { useAuthStore } from '../../store/authStore';
 import type { LoggingMode } from '../../store/authStoreTypes';
 import { IS_LINUX } from '../../utils/platform';
-import { showToast } from '../../utils/toast';
+import { showToast } from '../../utils/ui/toast';
 import { AboutPsysonicBrandHeader } from '../AboutPsysonicLol';
 import CustomSelect from '../CustomSelect';
 import LicensesPanel from '../LicensesPanel';

src/components/settings/UserForm.tsx

@@ -2,12 +2,12 @@ import React, { useEffect, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import { Eye, EyeOff, Shield, Wand2 } from 'lucide-react';
 import { ndUpdateUser, type NdLibrary, type NdUser } from '../../api/navidromeAdmin';
-import { showToast } from '../../utils/toast';
+import { showToast } from '../../utils/ui/toast';
 import {
   copyTextToClipboard,
   encodeServerMagicString,
-} from '../../utils/serverMagicString';
-import { shortHostFromServerUrl } from '../../utils/serverDisplayName';
+} from '../../utils/server/serverMagicString';
+import { shortHostFromServerUrl } from '../../utils/server/serverDisplayName';
 
 export interface UserFormState {
   userName: string;

src/components/settings/audio/AudioOutputDeviceSection.tsx

@@ -6,7 +6,7 @@ import CustomSelect from '../../CustomSelect';
 import SettingsSubSection from '../../SettingsSubSection';
 import { useAuthStore } from '../../../store/authStore';
 import { IS_MACOS } from '../../../utils/platform';
-import { buildAudioDeviceSelectOptions } from '../../../utils/audioDeviceLabels';
+import { buildAudioDeviceSelectOptions } from '../../../utils/audio/audioDeviceLabels';
 
 interface Props {
   audioDevices: string[];

src/components/settings/userMgmt/MagicStringModal.tsx

@@ -3,12 +3,12 @@ import { createPortal } from 'react-dom';
 import { X } from 'lucide-react';
 import type { TFunction } from 'i18next';
 import { ndUpdateUser, type NdUser } from '../../../api/navidromeAdmin';
-import { showToast } from '../../../utils/toast';
+import { showToast } from '../../../utils/ui/toast';
 import {
   copyTextToClipboard,
   encodeServerMagicString,
-} from '../../../utils/serverMagicString';
-import { shortHostFromServerUrl } from '../../../utils/serverDisplayName';
+} from '../../../utils/server/serverMagicString';
+import { shortHostFromServerUrl } from '../../../utils/server/serverDisplayName';
 
 interface Props {
   user: NdUser;

src/components/settings/userMgmt/UserMgmtRow.tsx

@@ -2,7 +2,7 @@ import React from 'react';
 import { Shield, Trash2, User, Wand2 } from 'lucide-react';
 import type { i18n as I18nType, TFunction } from 'i18next';
 import type { NdLibrary, NdUser } from '../../../api/navidromeAdmin';
-import { formatLastSeen } from '../../../utils/userMgmtHelpers';
+import { formatLastSeen } from '../../../utils/componentHelpers/userMgmtHelpers';
 
 interface Props {
   user: NdUser;