fix(settings): make normalization modes exclusive and refine LUFS UI

Replace the mixed ReplayGain/Loudness controls with a single exclusive mode selector, hide RG-specific controls when LUFS is active, and align the queue tech badge behavior between RG and LUFS. Also update LUFS targets to -10..-16 ordering and default loudness target to -12.

src/components/QueuePanel.tsx

@@ -483,16 +483,16 @@ export default function QueuePanel() {
             const rgParts = formatQueueReplayGainParts(currentTrack, t);
             const baseLine = baseParts.join(' · ');
             const rgLine = rgParts.join(' · ');
+            const isLoudnessActive = normalizationEngine === 'loudness' || normalizationEngineLive === 'loudness';
             const liveGainLabel = normalizationNowDb != null
               ? `${normalizationNowDb >= 0 ? '+' : ''}${normalizationNowDb.toFixed(2)} dB`
               : '—';
-            const targetLabel = normalizationEngineLive === 'loudness'
-              ? (normalizationTargetLufs != null ? `${normalizationTargetLufs} LUFS` : '-16 LUFS')
-              : normalizationEngineLive === 'replaygain'
-                ? `ReplayGain (${replayGainMode})`
-                : t('queue.normOff', { defaultValue: 'Off' });
+            const targetLabel = normalizationTargetLufs != null
+              ? `${normalizationTargetLufs} LUFS`
+              : '-16 LUFS';
             if (!baseLine && !rgLine && !playbackSource) return null;
-            const showRgLine = expandReplayGain && !!rgLine;
+            const showRgLine = !isLoudnessActive && expandReplayGain && !!rgLine;
+            const showLufsLine = isLoudnessActive && expandReplayGain;
             return (
               <div className={`queue-current-tech${showRgLine ? ' queue-current-tech--two-line' : ''}`}>
                 <div className="queue-current-tech-stack">
@@ -515,7 +515,7 @@ export default function QueuePanel() {
                       </span>
                     )}
                     {baseLine && <span className="queue-current-tech-main">{baseLine}</span>}
-                    {rgLine && (
+                    {!isLoudnessActive && rgLine && (
                       <button
                         type="button"
                         className={`queue-current-tech-rg-badge${showRgLine ? ' queue-current-tech-rg-badge--open' : ''}`}
@@ -528,6 +528,19 @@ export default function QueuePanel() {
                         <ChevronDown size={9} strokeWidth={2.5} />
                       </button>
                     )}
+                    {isLoudnessActive && (
+                      <button
+                        type="button"
+                        className={`queue-current-tech-rg-badge${showLufsLine ? ' queue-current-tech-rg-badge--open' : ''}`}
+                        data-tooltip={`LUFS · ${liveGainLabel} · TGT · ${targetLabel}`}
+                        aria-expanded={showLufsLine}
+                        aria-label="LUFS"
+                        onClick={() => setExpandReplayGain(!expandReplayGain)}
+                      >
+                        LUFS
+                        <ChevronDown size={9} strokeWidth={2.5} />
+                      </button>
+                    )}
                   </div>
                   {showRgLine && (
                     <span className="queue-current-tech-rg">
@@ -535,12 +548,12 @@ export default function QueuePanel() {
                       {' · '}{rgLine}
                     </span>
                   )}
-                  {(normalizationEngine === 'loudness' || normalizationEngineLive === 'loudness') && (
+                  {showLufsLine && (
                     <span className="queue-current-tech-rg">
-                      <span className="queue-current-tech-rg-label">{t('queue.normNow', { defaultValue: 'Now' })}</span>
+                      <span className="queue-current-tech-rg-label">Loudness</span>
                       {' · '}{liveGainLabel}
                       {' · '}
-                      <span className="queue-current-tech-rg-label">{t('queue.normTarget', { defaultValue: 'Target' })}</span>
+                      <span className="queue-current-tech-rg-label">TGT</span>
                       {' · '}{targetLabel}
                     </span>
                   )}

src/pages/Settings.tsx

@@ -2217,59 +2217,67 @@ export default function Settings() {
             icon={<Music2 size={16} />}
           >
             <div className="settings-card">
-              {/* Replay Gain */}
+              {/* Normalization */}
               <div className="settings-toggle-row">
                 <div>
-                  <div style={{ fontWeight: 500 }}>{t('settings.replayGain')}</div>
-                  <div style={{ fontSize: 12, color: 'var(--text-muted)' }}>{t('settings.replayGainDesc')}</div>
-                </div>
-                <label className="toggle-switch" aria-label={t('settings.replayGain')}>
-                  <input
-                    type="checkbox"
-                    checked={auth.replayGainEnabled}
-                    onChange={e => {
-                      const on = e.target.checked;
-                      auth.setReplayGainEnabled(on);
-                      if (!on) auth.setNormalizationEngine('off');
-                      else if (auth.normalizationEngine === 'off') auth.setNormalizationEngine('replaygain');
-                    }}
-                    id="replay-gain-toggle"
-                  />
-                  <span className="toggle-track" />
-                </label>
-              </div>
-              {auth.replayGainEnabled && (
-                <div style={{ paddingLeft: '1rem', marginTop: '0.5rem', display: 'flex', flexDirection: 'column', gap: '0.4rem' }}>
-                  <div style={{ display: 'flex', alignItems: 'center', gap: '0.75rem', flexWrap: 'wrap' }}>
-                    <span style={{ fontSize: 13, color: 'var(--text-secondary)' }}>Engine:</span>
-                    <button
-                      className={`btn ${auth.normalizationEngine === 'replaygain' ? 'btn-primary' : 'btn-ghost'}`}
-                      style={{ fontSize: 12, padding: '3px 12px' }}
-                      onClick={() => auth.setNormalizationEngine('replaygain')}
-                    >
-                      ReplayGain
-                    </button>
-                    <button
-                      className={`btn ${auth.normalizationEngine === 'loudness' ? 'btn-primary' : 'btn-ghost'}`}
-                      style={{ fontSize: 12, padding: '3px 12px' }}
-                      onClick={() => auth.setNormalizationEngine('loudness')}
-                    >
-                      Loudness
-                    </button>
+                  <div style={{ fontWeight: 500 }}>{t('settings.normalization', { defaultValue: 'Normalization' })}</div>
+                  <div style={{ fontSize: 12, color: 'var(--text-muted)' }}>
+                    {t('settings.normalizationDesc', { defaultValue: 'Choose one normalization mode: ReplayGain or Loudness (LUFS).' })}
                   </div>
+                </div>
+                <div style={{ display: 'flex', alignItems: 'center', gap: '0.5rem' }}>
+                  <button
+                    className={`btn ${auth.normalizationEngine === 'off' ? 'btn-primary' : 'btn-ghost'}`}
+                    style={{ fontSize: 12, padding: '3px 10px' }}
+                    onClick={() => {
+                      auth.setReplayGainEnabled(false);
+                      auth.setNormalizationEngine('off');
+                    }}
+                  >
+                    Off
+                  </button>
+                  <button
+                    className={`btn ${auth.normalizationEngine === 'replaygain' ? 'btn-primary' : 'btn-ghost'}`}
+                    style={{ fontSize: 12, padding: '3px 10px' }}
+                    onClick={() => {
+                      auth.setReplayGainEnabled(true);
+                      auth.setNormalizationEngine('replaygain');
+                    }}
+                  >
+                    RG
+                  </button>
+                  <button
+                    className={`btn ${auth.normalizationEngine === 'loudness' ? 'btn-primary' : 'btn-ghost'}`}
+                    style={{ fontSize: 12, padding: '3px 10px' }}
+                    onClick={() => {
+                      auth.setReplayGainEnabled(false);
+                      if (auth.normalizationEngine !== 'loudness') auth.setLoudnessTargetLufs(-12);
+                      auth.setNormalizationEngine('loudness');
+                    }}
+                  >
+                    LUFS
+                  </button>
+                </div>
+              </div>
+              {auth.normalizationEngine !== 'off' && (
+                <div style={{ paddingLeft: '1rem', marginTop: '0.5rem', display: 'flex', flexDirection: 'column', gap: '0.4rem' }}>
                   {auth.normalizationEngine === 'loudness' && (
                     <>
-                      <div style={{ fontSize: 12, color: 'var(--text-muted)' }}>
-                        Apple-like automatic normalization. ReplayGain tags are ignored in this mode.
-                      </div>
                       <div style={{ display: 'flex', alignItems: 'center', gap: '0.75rem', flexWrap: 'wrap' }}>
                         <span style={{ fontSize: 13, color: 'var(--text-secondary)' }}>Target LUFS:</span>
                         <button
-                          className={`btn ${auth.loudnessTargetLufs === -16 ? 'btn-primary' : 'btn-ghost'}`}
+                          className={`btn ${auth.loudnessTargetLufs === -10 ? 'btn-primary' : 'btn-ghost'}`}
                           style={{ fontSize: 12, padding: '3px 12px' }}
-                          onClick={() => auth.setLoudnessTargetLufs(-16)}
+                          onClick={() => auth.setLoudnessTargetLufs(-10)}
                         >
-                          -16
+                          -10
+                        </button>
+                        <button
+                          className={`btn ${auth.loudnessTargetLufs === -12 ? 'btn-primary' : 'btn-ghost'}`}
+                          style={{ fontSize: 12, padding: '3px 12px' }}
+                          onClick={() => auth.setLoudnessTargetLufs(-12)}
+                        >
+                          -12
                         </button>
                         <button
                           className={`btn ${auth.loudnessTargetLufs === -14 ? 'btn-primary' : 'btn-ghost'}`}
@@ -2279,11 +2287,11 @@ export default function Settings() {
                           -14
                         </button>
                         <button
-                          className={`btn ${auth.loudnessTargetLufs === -12 ? 'btn-primary' : 'btn-ghost'}`}
+                          className={`btn ${auth.loudnessTargetLufs === -16 ? 'btn-primary' : 'btn-ghost'}`}
                           style={{ fontSize: 12, padding: '3px 12px' }}
-                          onClick={() => auth.setLoudnessTargetLufs(-12)}
+                          onClick={() => auth.setLoudnessTargetLufs(-16)}
                         >
-                          -12
+                          -16
                         </button>
                       </div>
                     </>
@@ -2321,7 +2329,7 @@ export default function Settings() {
                   )}
                 </div>
               )}
-              {auth.replayGainEnabled && auth.normalizationEngine === 'replaygain' && (
+              {auth.normalizationEngine === 'replaygain' && (
                 <div style={{ paddingLeft: '1rem', marginTop: '0.75rem', display: 'flex', flexDirection: 'column', gap: '0.6rem' }}>
                   <div style={{ display: 'flex', alignItems: 'center', gap: '0.75rem', flexWrap: 'wrap' }}>
                     <span style={{ fontSize: 13, color: 'var(--text-secondary)', minWidth: 100 }}>

src/store/authStore.ts

@@ -51,7 +51,7 @@ interface AuthState {
   customGenreBlacklist: string[];
   replayGainEnabled: boolean;
   normalizationEngine: NormalizationEngine;
-  loudnessTargetLufs: -16 | -14 | -12;
+  loudnessTargetLufs: -16 | -14 | -12 | -10;
   replayGainMode: 'track' | 'album' | 'auto';
   replayGainPreGainDb: number;   // added to RG gain for tagged files (0…+6 dB)
   replayGainFallbackDb: number;  // gain for untagged files / radio (-6…0 dB)
@@ -209,7 +209,7 @@ interface AuthState {
   setCustomGenreBlacklist: (v: string[]) => void;
   setReplayGainEnabled: (v: boolean) => void;
   setNormalizationEngine: (v: NormalizationEngine) => void;
-  setLoudnessTargetLufs: (v: -16 | -14 | -12) => void;
+  setLoudnessTargetLufs: (v: -16 | -14 | -12 | -10) => void;
   setReplayGainMode: (v: 'track' | 'album' | 'auto') => void;
   setReplayGainPreGainDb: (v: number) => void;
   setReplayGainFallbackDb: (v: number) => void;
@@ -321,7 +321,7 @@ export const useAuthStore = create<AuthState>()(
       customGenreBlacklist: [],
       replayGainEnabled: false,
       normalizationEngine: 'off',
-      loudnessTargetLufs: -14,
+      loudnessTargetLufs: -12,
       replayGainMode: 'auto',
       replayGainPreGainDb: 0,
       replayGainFallbackDb: 0,