Add Slice 5 ADAU1701 runtime audio control (firmware 0.5.0).

Safeload mixer/EQ/master on the ADAU1701, persist AudioProfile in NVS,
expose /api/audio routes and web UI controls, with host tests and manual sync.

Co-authored-by: Cursor <cursoragent@cursor.com>

Software/main/CMakeLists.txt

@@ -3,5 +3,5 @@ idf_component_register(
         "main.cpp"
         "hardware_bootstrap.cpp"
     INCLUDE_DIRS "."
-    REQUIRES core net secure_store adau1701 si4684 tuner
+    REQUIRES core net secure_store adau1701 si4684 tuner audio
 )

Software/main/hardware_bootstrap.cpp

@@ -14,7 +14,10 @@
 #include "hardware_bootstrap.hpp"
 
 #include "adau1701/Adau1701Driver.hpp"
+#include "adau1701/Adau1701Dsp.hpp"
+#include "audio/AudioService.hpp"
 #include "board_pins.hpp"
+#include "secure_store/NvsAudioProfileStore.hpp"
 #include "si4684/Si4684Band.hpp"
 #include "si4684/Si4684Driver.hpp"
 #include "si4684/Si4684EmbeddedImages.hpp"
@@ -51,6 +54,9 @@ adau1701::Adau1701Driver gAdau1701(
         .resetGpio = board::pins::Adau1701Reset,
         .i2cAddr7 = board::pins::Adau1701Addr,
     });
+adau1701::Adau1701Dsp gAdau1701Dsp(gAdau1701);
+secure_store::NvsAudioProfileStore gAudioStore;
+audio::AudioService gAudioService(gAdau1701Dsp, &gAudioStore);
 
 bool gReady = false;
 } // namespace
@@ -74,6 +80,10 @@ std::expected<void, HardwareBootError> HardwareBootstrap::boot()
         }
     }
 
+    if (auto audioResult = gAudioService.loadAndApply(); !audioResult) {
+        ESP_LOGW(kTag, "ADAU1701 profile apply failed");
+    }
+
     gReady = true;
     ESP_LOGI(kTag, "companion chips ready");
     return {};
@@ -84,4 +94,9 @@ si4684::Si4684Tuner& HardwareBootstrap::si4684Tuner()
     return gSi4684Tuner;
 }
 
+audio::AudioService& HardwareBootstrap::audioService()
+{
+    return gAudioService;
+}
+
 } // namespace hardware

Software/main/hardware_bootstrap.hpp

@@ -14,6 +14,10 @@
 
 #include <expected>
 
+namespace audio {
+class AudioService;
+} // namespace audio
+
 namespace si4684 {
 class Si4684Tuner;
 } // namespace si4684
@@ -75,6 +79,20 @@ public:
      * @date     2026-07-06
      */
     [[nodiscard]] static si4684::Si4684Tuner& si4684Tuner();
+
+    /**
+     * @brief    audioService — borrow the audio orchestration service after boot.
+     *
+     * @dname    audioService
+     * @return   Reference to the static AudioService instance.
+     * @pubstate reads static storage initialised by boot().
+     *
+     * Valid only after a successful boot() call in the same process.
+     *
+     * @author   Michele Bigi
+     * @date     2026-07-06
+     */
+    [[nodiscard]] static audio::AudioService& audioService();
 };
 
 } // namespace hardware

Software/main/main.cpp

@@ -47,7 +47,7 @@ void heartbeatTask(void* arg)
  */
 extern "C" void app_main()
 {
-    ESP_LOGI(kTag, "DigiRadio firmware boot — Slice 4");
+    ESP_LOGI(kTag, "DigiRadio firmware boot — Slice 5");
 
     auto hwResult = hardware::HardwareBootstrap::boot();
     if (!hwResult) {
@@ -60,7 +60,8 @@ extern "C" void app_main()
 
     static secure_store::NvsSecureStore store;
 
-    auto netResult = net::NetBootstrap::start(store, tunerService);
+    auto netResult = net::NetBootstrap::start(
+        store, tunerService, hardware::HardwareBootstrap::audioService());
     if (!netResult) {
         ESP_LOGE(kTag, "network bootstrap failed");
         return;