Address PR review feedback from liamcottle (second round)

- Rename eth command to eth.status for consistency with other commands
- Rename generateDeviceMac to generateEthernetMac for clarity
- Refactor ethernet_handle_command to return false by default
- Allow new TCP clients to replace existing connections (repeater, room server, SerialEthernetInterface)
- Boot companion radio without Ethernet on init failure (LoRa-only recovery mode)
- Remove > prompt from ethernet CLI for consistency with serial interface
- Fix variable redeclaration compile error in SerialEthernetInterface when ETHERNET_STATIC_IP is defined
- Fix TCP socket leak when duplicate client detection fires
- Remove dead recv_queue and adv_restart_time members from SerialEthernetInterface
- Fix port numbers in docs (port 23 for repeater/room server CLI, port 5000 for companion radio)
- Clarify eth.status command is only available in repeater and room server firmware

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

examples/companion_radio/main.cpp

@@ -160,6 +160,7 @@ void setup() {
 
 #ifdef BLE_PIN_CODE
   serial_interface.begin(BLE_NAME_PREFIX, the_mesh.getNodePrefs()->node_name, the_mesh.getBLEPin());
+  the_mesh.startInterface(serial_interface);
 #elif defined(ETHERNET_ENABLED)
   Serial.print("Waiting for serial to connect...\n");
   time_t timeout = millis();
@@ -167,14 +168,15 @@ void setup() {
     if ((millis() - timeout) < 5000) { delay(100); } else { break; }
   }
   Serial.println("Initializing Ethernet adapter...");
-  if (!serial_interface.begin()) {
-    Serial.println("ETH: Init failed, halting");
-    halt();
+  if (serial_interface.begin()) {
+    the_mesh.startInterface(serial_interface);
+  } else {
+    Serial.println("ETH: Init failed, continuing without Ethernet (mesh only)");
   }
 #else
   serial_interface.begin(Serial);
-#endif
   the_mesh.startInterface(serial_interface);
+#endif
 #elif defined(RP2040_PLATFORM)
   LittleFS.begin();
   store.begin();