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/BroadcastLabel.cpp

@@ -0,0 +1,58 @@
+/**
+ * @file    BroadcastLabel.cpp
+ * @brief   BroadcastLabel 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/BroadcastLabel.hpp"
+
+namespace core {
+
+namespace {
+
+[[nodiscard]] std::string trimChipPadding(std::string_view raw)
+{
+    std::size_t end = raw.size();
+    if (end > BroadcastLabel::kMaxLength) {
+        end = BroadcastLabel::kMaxLength;
+    }
+    while (end > 0U && (raw[end - 1U] == '\0' || raw[end - 1U] == ' ')) {
+        --end;
+    }
+    std::size_t start = 0U;
+    while (start < end && raw[start] == ' ') {
+        ++start;
+    }
+    return std::string(raw.substr(start, end - start));
+}
+
+} // namespace
+
+std::optional<BroadcastLabel> BroadcastLabel::tryFromChipBytes(
+    std::string_view raw)
+{
+    const std::string trimmed = trimChipPadding(raw);
+    if (trimmed.empty()) {
+        return std::nullopt;
+    }
+    return BroadcastLabel(trimmed);
+}
+
+BroadcastLabel::BroadcastLabel(std::string label)
+    : label_(std::move(label))
+{
+}
+
+std::string_view BroadcastLabel::value() const noexcept
+{
+    return label_;
+}
+
+} // namespace core