Initial commit: RNodeTHV4 boundary mode firmware for Heltec V4

Bridges LoRa mesh and TCP/WiFi backbone networks using microReticulum.
Based on microReticulum_Firmware with boundary mode additions:
- BoundaryMode.h: State management and EEPROM persistence
- BoundaryConfig.h: WiFi captive portal for configuration
- TcpInterface.h: TCP backbone interface with HDLC framing
- Display.h: Custom OLED layout with network status indicators
- Transport/Identity library patches for embedded memory constraints

.gitignore

@@ -0,0 +1,11 @@
+.DS_Store
+*.hex
+*.pyc
+TODO
+Release/*.hex
+Release/*.zip
+Release/*.json
+Console/build
+build/*
+.pio/*
+.vscode/*