Offband offband-v0.18.0

Added

• Heltec V4 TFT observer build (heltec_v4_tft_companion_observer_wifi) — the
  observer role on the TFT (ST7789) display variant, switched to the NimBLE stack
  the observer requires. Added to the CI build matrix and the release env set so it
  always builds and ships.

Changed

• Firmware download clarity — a "Which file?" table in the README and a static
  footer appended to every GitHub Release, explaining -merged.bin (first install)
  vs .bin (update) vs .uf2 (nRF52).

Fixed

• pio-flash device matching — find_in_registry prefers an exact
  DeviceID-instance match over a class-only label, so a registered chip is no longer
  shadowed by a same-class device with null discriminators (fixes nRF52/ESP32
  mislabels where two boards share a VID:PID).

Internal

• Wire a gitignored HARDWARE.local.md (symlink to the LoRa hardware inventory) plus
  a CLAUDE.md "read before any hardware work" pointer.

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Which file do I download?

File	What it is	When to use it
*-merged.bin (ESP32 — Heltec V3/V4, XIAO)	Full image — bootloader + partition table + app in one, flashed at 0x0 after a chip erase. Self-contained, works on a blank chip.	First install / clean setup. In a web flasher this is the "Full Firmware" option.
*.bin (ESP32)	App only — flashed at the app offset (0x10000); the bootloader must already be on the chip.	Updating an existing node — OTA / "Update Only." Keeps the device identity + WiFi/MQTT config.
*.uf2 (nRF52 — RAK, T-Echo, XIAO nRF52)	Complete self-contained image.	First install and updates — double-tap reset, then drag-drop onto the USB drive. (nRF52 has no merged/app split.)

⚠️ ESP32: the app-only *.bin will not boot if flashed at 0x0 — use *-merged.bin for a fresh install. A full erase / "Full Firmware" wipes the device's identity + saved config, so use it only for a first install or recovery, never a routine update.

What's Changed

• docs(#127): MeshCore 1.16.0 base-update merge plan by @Strycher in #133
• feat: Heltec V4 TFT observer build (always-build) + flash docs & tooling by @Strycher in #138

Full Changelog: offband-v0.17.0...offband-v0.18.0