Add integration startup service and fix Doxygen (fw 0.8.1).

Replace the services stub with IntegrationService for boot preset recall and tune orchestration, persist last preset in NVS, and remove invalid @return tags that broke CI on T4 metadata headers.

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

Software/components/core/include/core/DabDynamicLabelAccumulator.hpp

@@ -38,7 +38,6 @@ public:
      * @brief    reset — discard accumulated DLS segments.
      *
      * @dname    reset
-     * @return   n/a
      * @pubstate clears buffer and segment flags.
      *
      * @author   Michele Bigi
@@ -53,7 +52,6 @@ public:
      * @param    segmentIndex  Zero-based segment index from the chip.
      * @param    segmentCount  Total segments advertised for this label.
      * @param    payload       Raw UTF-8 bytes for this segment.
-     * @return   n/a
      * @pubstate copies payload into buffer_ at the computed offset.
      *
      * @author   Michele Bigi

Software/components/core/include/core/ISecureStore.hpp

@@ -20,6 +20,7 @@
 #include "core/StoreError.hpp"
 #include "core/WifiCredentials.hpp"
 
+#include <cstdint>
 #include <expected>
 #include <string>
 #include <string_view>
@@ -157,6 +158,58 @@ public:
      */
     [[nodiscard]] virtual std::expected<void, StoreError>
     clearStationList() = 0;
+
+    /**
+     * @brief    hasLastPresetIndex — check whether a last-recalled preset exists.
+     *
+     * @dname    hasLastPresetIndex
+     * @return   true when loadLastPresetIndex would succeed.
+     * @pubstate reads backing storage via implementation.
+     *
+     * @author   Michele Bigi
+     * @date     2026-07-06
+     */
+    [[nodiscard]] virtual bool hasLastPresetIndex() const = 0;
+
+    /**
+     * @brief    saveLastPresetIndex — persist the last recalled preset index.
+     *
+     * @dname    saveLastPresetIndex
+     * @param    index  Zero-based preset list position (0–19).
+     * @return   Ok on success, or StoreError::IoFailed.
+     * @pubstate writes backing storage via implementation.
+     *
+     * @author   Michele Bigi
+     * @date     2026-07-06
+     */
+    [[nodiscard]] virtual std::expected<void, StoreError>
+    saveLastPresetIndex(std::uint8_t index) = 0;
+
+    /**
+     * @brief    loadLastPresetIndex — read the last recalled preset index.
+     *
+     * @dname    loadLastPresetIndex
+     * @return   Preset index on success, or StoreError.
+     * @pubstate reads backing storage via implementation.
+     *
+     * @author   Michele Bigi
+     * @date     2026-07-06
+     */
+    [[nodiscard]] virtual std::expected<std::uint8_t, StoreError>
+    loadLastPresetIndex() const = 0;
+
+    /**
+     * @brief    clearLastPresetIndex — erase the last-recalled preset marker.
+     *
+     * @dname    clearLastPresetIndex
+     * @return   Ok on success, or StoreError::IoFailed.
+     * @pubstate clears backing storage via implementation.
+     *
+     * @author   Michele Bigi
+     * @date     2026-07-06
+     */
+    [[nodiscard]] virtual std::expected<void, StoreError>
+    clearLastPresetIndex() = 0;
 };
 
 } // namespace core

Software/components/core/include/core/IntegrationError.hpp

@@ -0,0 +1,34 @@
+/**
+ * @file    IntegrationError.hpp
+ * @brief   Typed errors for application integration flows.
+ *
+ * DigiRadio firmware — https://github.com/manvalan/DigiRadio
+ *
+ * Copyright 2026 Michele Bigi
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * @author  Michele Bigi
+ * @date    2026-07-06
+ */
+#pragma once
+
+namespace core {
+
+/**
+ * @brief    IntegrationError — failure causes for preset recall orchestration.
+ *
+ * @dname    IntegrationError
+ * @return   n/a (type)
+ * @pubstate n/a
+ *
+ * @author   Michele Bigi
+ * @date     2026-07-06
+ */
+enum class IntegrationError {
+    StoreFailed,    ///< NVS load/save failed during startup or recall.
+    PresetNotFound, ///< Preset index out of range.
+    TuneFailed,     ///< Tuner could not recall the preset target.
+    AudioFailed,    ///< ADAU1701 profile could not be applied.
+};
+
+} // namespace core

Software/components/core/include/core/RdsMetadataAccumulator.hpp

@@ -36,7 +36,6 @@ public:
      * @brief    reset — clear accumulated PS and radiotext.
      *
      * @dname    reset
-     * @return   n/a
      * @pubstate clears internal buffers.
      *
      * @author   Michele Bigi
@@ -52,7 +51,6 @@ public:
      * @param    blockB  RDS block B (group type and address).
      * @param    blockC  RDS block C (text payload).
      * @param    blockD  RDS block D (text payload for RT).
-     * @return   n/a
      * @pubstate updates PS/RT buffers for group types 0A and 2A.
      *
      * @author   Michele Bigi