Add ESP32 OTA firmware update with rollback confirmation.

Stream application binaries to the inactive OTA slot via POST /api/system/ota,
validate the esp_app_desc project name in core, and cancel rollback after a
healthy network boot through OtaService::confirmBoot().

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

Software/components/core/test/CMakeLists.txt

@@ -49,6 +49,7 @@ add_library(digiradio_core STATIC
     "${CORE_SRC_DIR}/DspProgram.cpp"
     "${CORE_SRC_DIR}/RegisterWrite.cpp"
     "${CORE_SRC_DIR}/DspProgramBlob.cpp"
+    "${CORE_SRC_DIR}/OtaAppDescriptor.cpp"
 )
 target_include_directories(digiradio_core PUBLIC
     "${CMAKE_CURRENT_SOURCE_DIR}/../include"
@@ -58,6 +59,10 @@ add_executable(dsp_program_blob_test dsp_program_blob_test.cpp)
 target_link_libraries(dsp_program_blob_test PRIVATE digiradio_core)
 add_test(NAME dsp_program_blob_test COMMAND dsp_program_blob_test)
 
+add_executable(ota_app_descriptor_test ota_app_descriptor_test.cpp)
+target_link_libraries(ota_app_descriptor_test PRIVATE digiradio_core)
+add_test(NAME ota_app_descriptor_test COMMAND ota_app_descriptor_test)
+
 add_executable(device_identity_test device_identity_test.cpp)
 target_link_libraries(device_identity_test PRIVATE digiradio_core)
 add_test(NAME device_identity_test COMMAND device_identity_test)

Software/components/core/test/ota_app_descriptor_test.cpp

@@ -0,0 +1,87 @@
+/**
+ * @file    ota_app_descriptor_test.cpp
+ * @brief   Host tests for OTA app descriptor validation.
+ *
+ * DigiRadio firmware — https://github.com/manvalan/DigiRadio
+ *
+ * Copyright 2026 Michele Bigi
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * @author  Michele Bigi
+ * @date    2026-07-07
+ */
+
+#include "core/OtaAppDescriptor.hpp"
+
+#include <array>
+#include <cassert>
+#include <cstring>
+#include <cstdint>
+
+namespace {
+
+void writeLe32(std::uint8_t* p, std::uint32_t value)
+{
+    p[0] = static_cast<std::uint8_t>(value);
+    p[1] = static_cast<std::uint8_t>(value >> 8);
+    p[2] = static_cast<std::uint8_t>(value >> 16);
+    p[3] = static_cast<std::uint8_t>(value >> 24);
+}
+
+std::array<std::uint8_t, 256> makeValidPrefix()
+{
+    std::array<std::uint8_t, 256> image{};
+    writeLe32(image.data() + core::kOtaAppDescriptorOffset,
+              core::kOtaAppDescriptorMagic);
+    std::memcpy(image.data() + core::kOtaAppDescriptorOffset + 40U,
+                core::kOtaProjectName,
+                std::strlen(core::kOtaProjectName));
+    return image;
+}
+
+void testValidDescriptor()
+{
+    const auto image = makeValidPrefix();
+    const auto result = core::validateOtaAppDescriptor(image);
+    assert(result.has_value());
+}
+
+void testInsufficientHeader()
+{
+    const std::array<std::uint8_t, 32> shortImage{};
+    const auto result = core::validateOtaAppDescriptor(shortImage);
+    assert(!result.has_value());
+    assert(result.error() == core::OtaImageError::InsufficientHeader);
+}
+
+void testInvalidMagic()
+{
+    auto image = makeValidPrefix();
+    writeLe32(image.data() + core::kOtaAppDescriptorOffset, 0U);
+    const auto result = core::validateOtaAppDescriptor(image);
+    assert(!result.has_value());
+    assert(result.error() == core::OtaImageError::InvalidMagic);
+}
+
+void testInvalidProject()
+{
+    auto image = makeValidPrefix();
+    const char foreign[] = "other-project";
+    std::memcpy(image.data() + core::kOtaAppDescriptorOffset + 40U,
+                foreign,
+                sizeof(foreign));
+    const auto result = core::validateOtaAppDescriptor(image);
+    assert(!result.has_value());
+    assert(result.error() == core::OtaImageError::InvalidProject);
+}
+
+} // namespace
+
+int main()
+{
+    testValidDescriptor();
+    testInsufficientHeader();
+    testInvalidMagic();
+    testInvalidProject();
+    return 0;
+}