Add Hammer board support and local configurator 🤖🤖

[BrokenCircuitRanch]

Summary

Adds a Hammer board variant with SX1262 LoRa, OLED, GPS, and optional W5500 Ethernet builds.

Also adds a local USB configurator script for repeater and room-server setup when the browser-based configurator is not available, plus Windows packaging helper docs.

Details

• Adds Hammer PlatformIO environments for repeater, room server, USB companion, BLE companion, Ethernet companion, and ESP-NOW bridge repeater.
• Adds Hammer-specific UART GPS handling without the generic I2C environment sensor path.
• Adds a guarded ESP32 W5500 serial Ethernet helper so non-Ethernet targets do not require Ethernet3.
• Adds HAS_ETHERNET handling to the ESP32 companion-radio interface selector so Hammer Ethernet uses the W5500 TCP interface.
• Documents the local configurator and firmware flashing helper in the README.

Repo-wide note

Many ESP32 variants include helpers/esp32/*.cpp through their PlatformIO source filters. The Ethernet helper is therefore guarded behind HAS_ETHERNET so those existing ESP32 variants do not need Ethernet3 and keep their current WiFi, BLE, or USB serial behavior. The companion-radio selector now recognizes HAS_ETHERNET, but only Ethernet-enabled builds use that path.

Validation

• pio run -e hammer_sx1262_repeater
• pio run -e hammer_sx1262_companion_ethernet
• pio run -e Heltec_v3_companion_radio_ble as a non-Ethernet ESP32 regression check