docs: solar collector and observed CWU heating pattern

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/roadmap.md

@@ -63,6 +63,8 @@ Sources: [research/frisko/](../research/frisko/README.md).
   read or write the intervals. Reading the schedule is therefore not read-only, and the selector
   is shared with the panel and the Frisko app. Party mode (4140 = 2, hours in 4142) is a simpler
   "heat now" override.
+- CWU today (Influx, 14 days): the pump heats it daily at ~11:00 and ~17:30 up to ~44 °C
+  (~15–20 °C/h, pump outlet ~47 °C). Slow morning rises with the pump off come from solar.
 - Phone app: direct Modbus TCP, LAN only, 200–300 ms between requests, 5 s timeout.
 - No SE21 manual for the control logic; `MR208-PC+_9P_v3.pdf` is the closest reference.
 - `frisko/mr208_m3p.csv` on `archive/spring-boot-attempt` is for MR208-M3+ and must not be used.

docs/spec.md

@@ -24,6 +24,7 @@ Grafana stays the tool for long-term analysis; the app shows up to 7 days of his
 |---|---|---|
 | Heat pump controller Frisko RX910-SE21, fw v24062015 | behind the gateway | Slow to respond; commands fail under frequent polling |
 | Gateway Frisko MK01 (DS1206/EM500) | `192.168.0.150:502` | Modbus TCP → RTU 9600 on RS485; **one TCP client at a time, a new one drops the old** |
+| Solar thermal collector | Krosno | Also heats the CWU tank; not connected to the controller as far as we know |
 | Raspberry Pi (`raspberrypi`) | Krosno LAN, `192.168.0.158` | Runs the backend (`home-pump.service`), WireGuard `10.0.0.2` |
 | My server | remote | Traefik, InfluxDB 1.x (`Dom_Pompa`), Grafana, Gitea |