fix: use explicit UTC-aware now() for hour alignment in Solcast provider

Matches the baseclass pattern and makes the current-hour computation
independent of the host timezone.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H5Q9tGhRPEWyc6t5H21DPW

Author: claude

src/batcontrol/forecastsolar/solcast.py

@@ -80,7 +80,7 @@ def get_forecast_from_raw_data(self) -> dict[int, float]:
         """
         results = self.get_all_raw_data()
 
-        now = datetime.datetime.now().astimezone(self.timezone)
+        now = datetime.datetime.now(datetime.timezone.utc).astimezone(self.timezone)
         current_hour_start = now.replace(minute=0, second=0, microsecond=0)
 
         prediction = {}