Fix TCP receive: path table update + interface naming + 10Mbps bitrate

- Fix path table insert bug: C++ map::insert() silently fails when key
  exists (unlike Python dict[key]=value). Changed to erase()+insert() so
  updated paths (e.g. local TCP replacing stale LoRa) actually take effect.
- Add name parameter to TcpInterface constructor to give each instance a
  unique identity hash, fixing map collision between backbone and local
  TCP server interfaces.
- Set TCP interface bitrate to 10 Mbps (was 500 bps) so Transport
  correctly prefers TCP paths over LoRa when both exist.
- Add PRG button hold >5s white screen indicator for config portal.
- Boundary mode cull_path_table: evict backbone paths first, preserving
  local paths needed for inbound routing.

TcpInterface.h

@@ -60,8 +60,9 @@ struct TcpClient {
 class TcpInterface : public RNS::InterfaceImpl {
 public:
     TcpInterface(TcpIfMode mode, uint16_t port = TCP_IF_DEFAULT_PORT,
-                 const char* target_host = nullptr, uint16_t target_port = 0)
-        : RNS::InterfaceImpl("TcpInterface"),
+                 const char* target_host = nullptr, uint16_t target_port = 0,
+                 const char* name = "TcpInterface")
+        : RNS::InterfaceImpl(name),
           _mode(mode),
           _port(port),
           _target_port(target_port),
@@ -77,11 +78,11 @@ public:
         _IN = true;
         _OUT = true;
         _HW_MTU = TCP_IF_HW_MTU;
-        // Report low bitrate + small announce_cap so that Transport
-        // rate-limits announce forwarding through this interface.
-        // Without this the backbone floods the ESP32 with announces.
-        // 500 bps ≈ LoRa-class throughput; announce_cap = 2% max bandwidth.
-        _bitrate = 500;
+        // TCP links are effectively 10 Mbps+. Setting a realistic
+        // bitrate lets Transport prefer TCP paths over LoRa when
+        // both exist for the same destination.
+        // announce_cap = 2% keeps backbone announce flooding in check.
+        _bitrate = 10000000;
         _announce_cap = 2.0;
         if (target_host != nullptr) {
             strncpy(_target_host, target_host, sizeof(_target_host) - 1);