Change: make sample rate read-only and auto-detected

The sample rate cannot be configured by users - it's determined by the audio
source (HDMI device or USB gadget client). The previous UI gave the false
impression that users could select a sample rate, but the value was always
overridden by hardware detection.

Changes:
- Convert sample rate UI from dropdown to read-only display
- Show "(auto-detected from source)" label next to the value
- Remove sampleRate parameter from setAudioConfig RPC
- Update translations to clarify auto-detection
- Backend sample rate validation remains for backwards compatibility

The C code now automatically detects and adapts to whatever rate the hardware
supports, creating the Opus encoder/decoder with matching parameters to
eliminate pitch/speed distortion.

jsonrpc.go

@@ -1078,7 +1078,7 @@ func rpcGetAudioConfig() (AudioConfigResponse, error) {
 	}, nil
 }
 
-func rpcSetAudioConfig(bitrate int, complexity int, dtxEnabled bool, fecEnabled bool, bufferPeriods int, sampleRate int, packetLossPerc int) error {
+func rpcSetAudioConfig(bitrate int, complexity int, dtxEnabled bool, fecEnabled bool, bufferPeriods int, packetLossPerc int) error {
 	ensureConfigLoaded()
 
 	if bitrate < 64 || bitrate > 256 {
@@ -1090,9 +1090,6 @@ func rpcSetAudioConfig(bitrate int, complexity int, dtxEnabled bool, fecEnabled
 	if bufferPeriods < 2 || bufferPeriods > 24 {
 		return fmt.Errorf("buffer periods must be between 2 and 24")
 	}
-	if sampleRate != 32000 && sampleRate != 44100 && sampleRate != 48000 && sampleRate != 96000 {
-		return fmt.Errorf("sample rate must be 32000, 44100, 48000, or 96000 Hz")
-	}
 	if packetLossPerc < 0 || packetLossPerc > 100 {
 		return fmt.Errorf("packet loss percentage must be between 0 and 100")
 	}
@@ -1102,7 +1099,6 @@ func rpcSetAudioConfig(bitrate int, complexity int, dtxEnabled bool, fecEnabled
 	config.AudioDTXEnabled = dtxEnabled
 	config.AudioFECEnabled = fecEnabled
 	config.AudioBufferPeriods = bufferPeriods
-	config.AudioSampleRate = sampleRate
 	config.AudioPacketLossPerc = packetLossPerc
 
 	return SaveConfig()
@@ -1454,7 +1450,7 @@ var rpcHandlers = map[string]RPCHandler{
 	"setAudioOutputSource":    {Func: rpcSetAudioOutputSource, Params: []string{"source"}},
 	"refreshHdmiConnection":   {Func: rpcRefreshHdmiConnection},
 	"getAudioConfig":          {Func: rpcGetAudioConfig},
-	"setAudioConfig":          {Func: rpcSetAudioConfig, Params: []string{"bitrate", "complexity", "dtxEnabled", "fecEnabled", "bufferPeriods", "sampleRate", "packetLossPerc"}},
+	"setAudioConfig":          {Func: rpcSetAudioConfig, Params: []string{"bitrate", "complexity", "dtxEnabled", "fecEnabled", "bufferPeriods", "packetLossPerc"}},
 	"restartAudioOutput":      {Func: rpcRestartAudioOutput},
 	"getAudioInputAutoEnable": {Func: rpcGetAudioInputAutoEnable},
 	"setAudioInputAutoEnable": {Func: rpcSetAudioInputAutoEnable, Params: []string{"enabled"}},

ui/localization/messages/da.json

@@ -89,7 +89,7 @@
     "audio_settings_buffer_title": "Bufferperioder",
     "audio_settings_buffer_description": "ALSA bufferstørrelse (højere = mere stabil, mere latens)",
     "audio_settings_sample_rate_title": "Samplingsrate",
-    "audio_settings_sample_rate_description": "Lydsamplingsfrekven (match HDMI-kilde for bedste kvalitet)",
+    "audio_settings_sample_rate_description": "Audio sampling frequency (automatically detected from source)",
     "audio_settings_packet_loss_title": "Pakketabskompensation",
     "audio_settings_packet_loss_description": "FEC overhead-procent (højere = bedre gendannelse, mere båndbredde)",
     "audio_settings_config_updated": "Lydkonfiguration opdateret",

ui/localization/messages/de.json

@@ -89,7 +89,7 @@
     "audio_settings_buffer_title": "Pufferperioden",
     "audio_settings_buffer_description": "ALSA-Puffergröße (höher = stabiler, mehr Latenz)",
     "audio_settings_sample_rate_title": "Abtastrate",
-    "audio_settings_sample_rate_description": "Audio-Abtastfrequenz (HDMI-Quelle anpassen für beste Qualität)",
+    "audio_settings_sample_rate_description": "Audio sampling frequency (automatically detected from source)",
     "audio_settings_packet_loss_title": "Paketverlust-Kompensation",
     "audio_settings_packet_loss_description": "FEC-Overhead-Prozentsatz (höher = bessere Wiederherstellung, mehr Bandbreite)",
     "audio_settings_config_updated": "Audiokonfiguration aktualisiert",

ui/localization/messages/en.json

@@ -89,7 +89,7 @@
     "audio_settings_buffer_title": "Buffer Periods",
     "audio_settings_buffer_description": "ALSA buffer size (higher = more stable, more latency)",
     "audio_settings_sample_rate_title": "Sample Rate",
-    "audio_settings_sample_rate_description": "Audio sampling frequency (match HDMI source for best quality)",
+    "audio_settings_sample_rate_description": "Audio sampling frequency (automatically detected from source)",
     "audio_settings_packet_loss_title": "Packet Loss Compensation",
     "audio_settings_packet_loss_description": "FEC overhead percentage (higher = better recovery, more bandwidth)",
     "audio_settings_config_updated": "Audio configuration updated",

ui/localization/messages/es.json

@@ -89,7 +89,7 @@
     "audio_settings_buffer_title": "Períodos de Buffer",
     "audio_settings_buffer_description": "Tamaño del buffer ALSA (mayor = más estable, más latencia)",
     "audio_settings_sample_rate_title": "Tasa de Muestreo",
-    "audio_settings_sample_rate_description": "Frecuencia de muestreo de audio (coincidir con fuente HDMI para mejor calidad)",
+    "audio_settings_sample_rate_description": "Audio sampling frequency (automatically detected from source)",
     "audio_settings_packet_loss_title": "Compensación de Pérdida de Paquetes",
     "audio_settings_packet_loss_description": "Porcentaje de sobrecarga FEC (mayor = mejor recuperación, más ancho de banda)",
     "audio_settings_config_updated": "Configuración de audio actualizada",

ui/localization/messages/fr.json

@@ -89,7 +89,7 @@
     "audio_settings_buffer_title": "Périodes de Tampon",
     "audio_settings_buffer_description": "Taille du tampon ALSA (plus élevé = plus stable, plus de latence)",
     "audio_settings_sample_rate_title": "Fréquence d'Échantillonnage",
-    "audio_settings_sample_rate_description": "Fréquence d'échantillonnage audio (correspondre à la source HDMI pour une meilleure qualité)",
+    "audio_settings_sample_rate_description": "Audio sampling frequency (automatically detected from source)",
     "audio_settings_packet_loss_title": "Compensation de Perte de Paquets",
     "audio_settings_packet_loss_description": "Pourcentage de surcharge FEC (plus élevé = meilleure récupération, plus de bande passante)",
     "audio_settings_config_updated": "Configuration audio mise à jour",

ui/localization/messages/it.json

@@ -89,7 +89,7 @@
     "audio_settings_buffer_title": "Periodi Buffer",
     "audio_settings_buffer_description": "Dimensione buffer ALSA (più alto = più stabile, più latenza)",
     "audio_settings_sample_rate_title": "Frequenza di Campionamento",
-    "audio_settings_sample_rate_description": "Frequenza di campionamento audio (abbinare alla sorgente HDMI per la migliore qualità)",
+    "audio_settings_sample_rate_description": "Audio sampling frequency (automatically detected from source)",
     "audio_settings_packet_loss_title": "Compensazione Perdita Pacchetti",
     "audio_settings_packet_loss_description": "Percentuale overhead FEC (più alto = migliore recupero, più banda)",
     "audio_settings_config_updated": "Configurazione audio aggiornata",

ui/localization/messages/nb.json

@@ -89,7 +89,7 @@
     "audio_settings_buffer_title": "Bufferperioder",
     "audio_settings_buffer_description": "ALSA bufferstørrelse (høyere = mer stabil, mer latens)",
     "audio_settings_sample_rate_title": "Samplingsrate",
-    "audio_settings_sample_rate_description": "Lydsampleringsfrekvens (match HDMI-kilde for beste kvalitet)",
+    "audio_settings_sample_rate_description": "Audio sampling frequency (automatically detected from source)",
     "audio_settings_packet_loss_title": "Pakketapskompensasjon",
     "audio_settings_packet_loss_description": "FEC overhead-prosent (høyere = bedre gjenoppretting, mer båndbredde)",
     "audio_settings_config_updated": "Lydkonfigurasjon oppdatert",

ui/localization/messages/sv.json

@@ -89,7 +89,7 @@
     "audio_settings_buffer_title": "Bufferperioder",
     "audio_settings_buffer_description": "ALSA bufferstorlek (högre = mer stabil, mer latens)",
     "audio_settings_sample_rate_title": "Samplingsfrekvens",
-    "audio_settings_sample_rate_description": "Ljudsamplingsfrekvens (matcha HDMI-källa för bästa kvalitet)",
+    "audio_settings_sample_rate_description": "Audio sampling frequency (automatically detected from source)",
     "audio_settings_packet_loss_title": "Paketförlustkompensation",
     "audio_settings_packet_loss_description": "FEC overhead-procent (högre = bättre återställning, mer bandbredd)",
     "audio_settings_config_updated": "Ljudkonfiguration uppdaterad",

ui/localization/messages/zh.json

@@ -89,7 +89,7 @@
     "audio_settings_buffer_title": "缓冲周期",
     "audio_settings_buffer_description": "ALSA 缓冲大小（越高 = 越稳定，延迟越高）",
     "audio_settings_sample_rate_title": "采样率",
-    "audio_settings_sample_rate_description": "音频采样频率（匹配 HDMI 源以获得最佳质量）",
+    "audio_settings_sample_rate_description": "Audio sampling frequency (automatically detected from source)",
     "audio_settings_packet_loss_title": "丢包补偿",
     "audio_settings_packet_loss_description": "FEC 开销百分比（越高 = 恢复越好，带宽越大）",
     "audio_settings_config_updated": "音频配置已更新",

ui/src/routes/devices.$id.settings.audio.tsx

@@ -120,12 +120,11 @@ export default function SettingsAudioRoute() {
     dtxEnabled: boolean,
     fecEnabled: boolean,
     bufferPeriods: number,
-    sampleRate: number,
     packetLossPerc: number
   ) => {
     send(
       "setAudioConfig",
-      { bitrate, complexity, dtxEnabled, fecEnabled, bufferPeriods, sampleRate, packetLossPerc },
+      { bitrate, complexity, dtxEnabled, fecEnabled, bufferPeriods, packetLossPerc },
       (resp: JsonRpcResponse) => {
         if ("error" in resp) {
           notifications.error(String(resp.error.data || m.unknown_error()));
@@ -136,7 +135,6 @@ export default function SettingsAudioRoute() {
         setAudioDTXEnabled(dtxEnabled);
         setAudioFECEnabled(fecEnabled);
         setAudioBufferPeriods(bufferPeriods);
-        setAudioSampleRate(sampleRate);
         setAudioPacketLossPerc(packetLossPerc);
         notifications.success(m.audio_settings_config_updated());
       }
@@ -217,7 +215,6 @@ export default function SettingsAudioRoute() {
                 audioDTXEnabled,
                 audioFECEnabled,
                 audioBufferPeriods,
-                audioSampleRate,
                 audioPacketLossPerc
               )
             }
@@ -245,7 +242,6 @@ export default function SettingsAudioRoute() {
                 audioDTXEnabled,
                 audioFECEnabled,
                 audioBufferPeriods,
-                audioSampleRate,
                 audioPacketLossPerc
               )
             }
@@ -265,7 +261,6 @@ export default function SettingsAudioRoute() {
                 e.target.checked,
                 audioFECEnabled,
                 audioBufferPeriods,
-                audioSampleRate,
                 audioPacketLossPerc
               )
             }
@@ -285,7 +280,6 @@ export default function SettingsAudioRoute() {
                 audioDTXEnabled,
                 e.target.checked,
                 audioBufferPeriods,
-                audioSampleRate,
                 audioPacketLossPerc
               )
             }
@@ -313,7 +307,6 @@ export default function SettingsAudioRoute() {
                 audioDTXEnabled,
                 audioFECEnabled,
                 parseInt(e.target.value),
-                audioSampleRate,
                 audioPacketLossPerc
               )
             }
@@ -324,27 +317,16 @@ export default function SettingsAudioRoute() {
           title={m.audio_settings_sample_rate_title()}
           description={m.audio_settings_sample_rate_description()}
         >
-          <SelectMenuBasic
-            size="SM"
-            value={String(audioSampleRate)}
-            options={[
-              { value: "32000", label: "32 kHz" },
-              { value: "44100", label: "44.1 kHz" },
-              { value: "48000", label: "48 kHz (default)" },
-              { value: "96000", label: "96 kHz" },
-            ]}
-            onChange={(e) =>
-              handleAudioConfigChange(
-                audioBitrate,
-                audioComplexity,
-                audioDTXEnabled,
-                audioFECEnabled,
-                audioBufferPeriods,
-                parseInt(e.target.value),
-                audioPacketLossPerc
-              )
-            }
-          />
+          <div className="text-sm text-gray-700 dark:text-gray-300 font-medium">
+            {audioSampleRate === 32000 && "32 kHz"}
+            {audioSampleRate === 44100 && "44.1 kHz"}
+            {audioSampleRate === 48000 && "48 kHz"}
+            {audioSampleRate === 96000 && "96 kHz"}
+            {![32000, 44100, 48000, 96000].includes(audioSampleRate) && `${audioSampleRate} Hz`}
+            <span className="text-xs text-gray-500 dark:text-gray-400 ml-2">
+              (auto-detected from source)
+            </span>
+          </div>
         </SettingsItem>
 
         <SettingsItem
@@ -370,7 +352,6 @@ export default function SettingsAudioRoute() {
                 audioDTXEnabled,
                 audioFECEnabled,
                 audioBufferPeriods,
-                audioSampleRate,
                 parseInt(e.target.value)
               )
             }