research: keep local polling, reject logger push to Server B

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01U8EHjVrf5ffw1Vjn5bPGJu

research/energy/README.md

@@ -33,3 +33,8 @@ The battery is configured as **backup only** (power cuts), on purpose: day and n
 runs on PV and the grid, so a full battery with ~0 W flow is the normal state.
 
 Fronius Symo 3.7 (`192.168.0.143`, Solar API JSON) produced another 4.4 kWh that day.
+
+Considered and rejected (2026-10-23): pointing the logger's second server ("Server B") at our
+backend. Push frames are poorly documented binary data every ~5 min, need a TCP server with
+acks, and a wrong setting could cut off the Solarman cloud my father uses. Local FC3 polling
+gives documented registers at our own rate. Server B stays empty; fallback only.