Add preset polish and broadcast metadata (fw 0.8.0).

Ship station reorder, DAB playing ids in presets, RDS PS/RT and DAB DLS in tuner status, Si4684 data-service read, host tests, and UI now-playing lines.

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

Software/components/core/src/DabDynamicLabelAccumulator.cpp

@@ -0,0 +1,70 @@
+/**
+ * @file    DabDynamicLabelAccumulator.cpp
+ * @brief   DabDynamicLabelAccumulator implementation.
+ *
+ * DigiRadio firmware — https://github.com/manvalan/DigiRadio
+ *
+ * Copyright 2026 Michele Bigi
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * @author  Michele Bigi
+ * @date    2026-07-06
+ */
+
+#include "core/DabDynamicLabelAccumulator.hpp"
+
+#include <algorithm>
+#include <cstring>
+
+namespace core {
+
+void DabDynamicLabelAccumulator::reset() noexcept
+{
+    buffer_.fill('\0');
+    segmentValid_.fill(false);
+    expectedSegments_ = 0U;
+}
+
+void DabDynamicLabelAccumulator::applySegment(
+    std::uint16_t segmentIndex,
+    std::uint16_t segmentCount,
+    std::span<const std::uint8_t> payload) noexcept
+{
+    if (segmentCount == 0U || segmentCount > kMaxSegments) {
+        return;
+    }
+    if (segmentIndex >= segmentCount) {
+        return;
+    }
+    if (expectedSegments_ != segmentCount) {
+        reset();
+        expectedSegments_ = segmentCount;
+    }
+
+    const std::size_t offset =
+        static_cast<std::size_t>(segmentIndex)
+        * static_cast<std::size_t>(payload.size());
+    if (offset >= buffer_.size()) {
+        return;
+    }
+    const std::size_t copyLen =
+        std::min(payload.size(), buffer_.size() - offset);
+    std::memcpy(buffer_.data() + offset, payload.data(), copyLen);
+    segmentValid_[segmentIndex] = true;
+}
+
+std::optional<BroadcastLabel> DabDynamicLabelAccumulator::label() const
+{
+    if (expectedSegments_ == 0U) {
+        return std::nullopt;
+    }
+    for (std::uint16_t i = 0U; i < expectedSegments_; ++i) {
+        if (!segmentValid_[i]) {
+            return std::nullopt;
+        }
+    }
+    return BroadcastLabel::tryFromChipBytes(
+        std::string_view(buffer_.data(), buffer_.size()));
+}
+
+} // namespace core