Show a warning instead of an empty canvas if the ionosonde station has no data, and also show a warning if we have data but it's old.

solarconditionsproviders/giroionosonde.py

@@ -35,6 +35,16 @@ class GIROIonosonde(SolarConditionsProvider):
                     stations.append({"ursi": row[0].strip(), "name": row[1].strip()})
         return stations
 
+    def setup(self, solar_conditions, solar_conditions_cache):
+        """Prepopulate the ionosonde_data map with known URSI and station names, so that the API exposes this structure
+        even before we actually have any data in it."""
+
+        super().setup(solar_conditions, solar_conditions_cache)
+        self.update_data({"ionosonde_data": {
+            s["ursi"]: {"ursi": s["ursi"], "name": s["name"], "fof2": None, "muf": None}
+            for s in self._stations
+        }})
+
     def start(self):
         logging.info(f"Set up query of GIRO ionosonde data API every {POLL_INTERVAL} seconds.")
         self._thread = Thread(target=self._run, daemon=True)