v0.5.2 — shared weather-station screenshot

Docs release. Adds the privacy-redacted ECOWITT WS90 dashboard screenshot to the "concrete example: a shared weather station" section of both READMEs (EN + DE).

This illustrates the integration's shared-device USP: a weather station paired to someone else's Shelly account, shared into yours, surfaced as native Home Assistant sensor entities via the self-service Cloud Control API — something a LAN-only integration structurally cannot reach.

No code changes; integration behaviour is identical to v0.5.1.