Covers 8 known issues encountered during multi-node ESP32-S3 deployments:
1. Node not appearing (limping state after USB flash)
2. Person count stuck at 1 (ADR-044)
3. Heart rate/breathing rate jitter (last-write-wins from multiple nodes)
4. Signal quality placeholder
5. Dashboard freezing (WS disconnect loop)
6. OTA crash at 59% (BLE vs OTA conflict)
7. SSH LAN hang (Tailscale workaround)
8. USB-C port selection
Helps with #268 (no nodes found), #375 (node_id), #366 (build errors).
b74fdcc733