v1.0.5: Heltec V3 support, heap stability fix, TCP reconnection improvements

- Add Heltec WiFi LoRa 32 V3 board support (8MB flash, 8MB PSRAM)
  - New heltec_V3_boundary build environment in platformio.ini
  - Board auto-detection in flash.py (8MB=V3, 16MB=V4)
  - V3 board definition in Boards.h
- Fix heap exhaustion causing watchdog reboots every ~70 min
  - Lower boundary_mentioned_addresses cap from 512 to 200
  - Heap now stable at ~38KB free (was draining to 0)
- TCP reconnection improvements in TcpInterface.h
  - SO_LINGER(0) for clean socket teardown
  - 10-minute read timeout prevents zombie connections
  - Defensive client cleanup on accept
- Add heap telemetry instrumentation (HEAP-TEL) for monitoring
- Add level guards on TRACE/DEBUG macros in Log.h
- Update README for dual V3/V4 board support

platformio.ini

@@ -309,6 +309,37 @@ lib_deps =
 	${env.lib_deps}
 	XPowersLib@^0.2.1
 
+[env:heltec_V3_boundary]
+platform = espressif32
+board = heltec_wifi_lora_32_V3
+custom_variant = heltec32v3
+board_build.filesystem = littlefs
+; Flash / memory layout for 8MB flash + 8MB PSRAM (QSPI)
+board_upload.flash_size = 8MB
+board_upload.maximum_size = 8388608
+board_build.partitions = default_8MB.csv
+board_build.flash_mode = qio
+board_build.psram_type = qio
+board_build.arduino.memory_type = qio_qspi
+monitor_speed = 115200
+build_flags = 
+	${env.build_flags}
+	-DBOARD_MODEL=BOARD_HELTEC32_V3
+	-DBOARD_HAS_PSRAM=1
+	-DBOUNDARY_MODE
+	;-DNDEBUG
+	-DRNS_USE_TLSF=1
+	-DRNS_USE_ALLOCATOR=1
+	; --- Boundary mode defaults (override via EEPROM at runtime) ---
+	; TCP server mode (0=server, 1=client)
+	-DBOUNDARY_TCP_MODE=0
+	; TCP listen/connect port
+	-DBOUNDARY_TCP_PORT=4242
+lib_deps =
+	${env.lib_deps}
+	XPowersLib@^0.2.1
+monitor_filters = esp32_exception_decoder
+
 [env:heltec_wifi_lora_32_V4]
 platform = espressif32
 board = esp32-s3-devkitc-1
@@ -342,7 +373,7 @@ build_flags =
 	-DARDUINO_USB_CDC_ON_BOOT=1
 	-DBOARD_HAS_PSRAM=1
 	-DBOUNDARY_MODE
-	-DNDEBUG
+	;-DNDEBUG
 	-DRNS_USE_TLSF=1
 	-DRNS_USE_ALLOCATOR=1
 	; --- Boundary mode defaults (override via EEPROM at runtime) ---