Implements #116 — hardware validation testing for edge crisis detector
on Raspberry Pi 4 and other edge devices.
Adds edge detector (keyword + optional Ollama model), crisis_resources.json,
deployment docs, and two test files:
- test_edge_detector.py: unit tests for keyword logic
- test_edge_detector_hardware.py: hardware validation suite
Hardware validation measures keyword detection (<1ms), model inference (<5s
on Pi 4), offline operation, and provides reproducible benchmark via
`python3 edge/detector.py --benchmark`.
Re-implements the functionality from closed PR #111 with expanded tests.
