"""
EMF Sensor Hardware Build Guide
Three-layer EMF sensing: Layer 1 (Schumann), Layer 2 (Individual), Layer 3 (Perturbation)

Budget tiers:
  free     — sound card + wire coil (VLF/ELF magnetic field)
  artist   — RTL-SDR USB dongle ($20, 0.5–1700 MHz)
  premium  — discone antenna + SDR (wideband, $50+)

All builds are Linux-native, Python 3, no exotic dependencies.
"""