LoRa Scanner: a MeshCore preset, and its packets read

- MeshCore joins the presets (EU/UK Narrow: 869.618 MHz, 62.5 kHz, SF8,
  CR 4/8, sync 0x12), after the Meshtastic ones so stored choices keep
  their number; `lora preset MeshCore` on the console
- lib/meshcore reads what MeshCore sends in clear: header, path, and a
  node's advert (name, kind, key, position)
- the list row, the details, a Capture's viewer and the console echo read
  a packet by the sync word it was received on
- the bandwidth is printed as 62.5, not 62

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0162FokPdvY2KsS4NBfwyWPk

src/apps/file_viewer.cpp

@@ -264,10 +264,9 @@ void FileViewer::openPacket(int index) {
     if (tap) {
         std::snprintf(line, sizeof line, "%.0f dBm, SNR %.1f dB, noise %.0f", rx.rssi, rx.snr, rx.noiseFloor);
         details_.push_back(line);
-        std::snprintf(line, sizeof line, "%.4f MHz, SF%u, %.0f kHz", rx.frequencyHz / 1e6, rx.spreadingFactor, rx.bandwidthKHz);
+        std::snprintf(line, sizeof line, "%.4f MHz, SF%u, %g kHz", rx.frequencyHz / 1e6, rx.spreadingFactor, rx.bandwidthKHz);
         details_.push_back(line);
-        if (rx.syncWord == meshtastic::kSyncWord)
-            for (auto& l : lora::headerLines(body + skip, have - skip)) details_.push_back(l);
+        for (auto& l : lora::headerLines(body + skip, have - skip, lora::protocolOf(rx.syncWord))) details_.push_back(l);
     }
     for (auto& l : lora::hexDump(body + skip, have - skip)) details_.push_back(l);
     if (have < r.length) details_.push_back("(the first bytes only)");
@@ -391,7 +390,7 @@ void FileViewer::refresh() {
             size_t have = std::min<size_t>(r.length, n - files::kPcapRecordSize);
             if (tap && files::parseLoraTap(body, have, rx)) {
                 shown_.push_back(lora::row({body + lora::kLoraTapSize, have - lora::kLoraTapSize, rx.rssi, rx.snr, true,
-                                            rx.syncWord == meshtastic::kSyncWord},
+                                            lora::protocolOf(rx.syncWord)},
                                            clockTime(r.seconds)));
             } else {
                 shown_.push_back(clockTime(r.seconds) + "  " + std::to_string(r.length) + " bytes");