- Add top-level README.md with project overview
- Add project-local 3D STEP models under hardware/lib/3d/
  * 1060TR.stp (Keystone coin cell holder)
  * CX2016SA32000D0WRQG1.stp (crystal)
  * LTST-C190KGKT.stp (LED)
  * NRF52805-CAAA-R7.stp (MCU)
- Add project-local footprints under hardware/lib/footprints/
  * FPC connectors (5-pin, 10-pin)
  * Johanson 2450AT42B100 antenna
  * Keystone 1060TR
  * LiteOn LEDC1608X80N
  * Nordic nRF52805 WLCSP
- Add project-local symbol libraries under hardware/lib/symbols/
  * Keystone, LiteOn, Nordic, Segger
- Move KiCad project files into hardware/ directory
  * nRF52805_temp_sensor.kicad_pro
  * nRF52805_temp_sensor.kicad_sch
  * nRF52805_temp_sensor.kicad_pcb