fix(weather): use stable instanceId to prevent duplicate fetchers (#4092)

During the server-side migration (PR #4032), the `instanceId` was built
with `Date.now()`, making it unique per client reload. This approach was
fine in the old browser-based architecture where reloads cleaned up
everything automatically. But now the node_helper persists across
reloads, so each reconnect created a new `HTTPFetcher` while the old one
kept polling - silently multiplying API calls over time.

The fix is simple: use `this.identifier` as the `instanceId`, which is
already stable and unique per module slot. This is the same approach the
Calendar module uses.

On the node_helper side, when a provider already exists for the same
`instanceId`, we now skip re-creation and just resend
`WEATHER_INITIALIZED` so the client picks up where it left off.

Fixes https://forum.magicmirror.builders/topic/20199

Author: KristjanESPERANTO

defaultmodules/weather/node_helper.js

@@ -31,7 +31,12 @@ module.exports = NodeHelper.create({
 		Log.log(`Attempting to initialize provider ${identifier} for instance ${instanceId}`);
 
 		if (this.providers[instanceId]) {
-			Log.log(`Weather provider ${identifier} already initialized for instance ${instanceId}`);
+			Log.log(`Weather provider ${identifier} already initialized for instance ${instanceId}, re-sending WEATHER_INITIALIZED`);
+			// Client may have restarted (e.g. page reload) - re-send so it recovers location name
+			this.sendSocketNotification("WEATHER_INITIALIZED", {
+				instanceId,
+				locationName: this.providers[instanceId].locationName
+			});
 			return;
 		}
 

defaultmodules/weather/weather.js

@@ -110,8 +110,8 @@ Module.register("weather", {
 			this.config.showHumidity = this.config.showHumidity ? "wind" : "none";
 		}
 
-		// All providers run server-side: generate unique instance ID and initialize via node_helper
-		this.instanceId = `${this.identifier}_${Date.now()}`;
+		// All providers run server-side: use stable identifier so reconnects don't spawn duplicate HTTPFetchers
+		this.instanceId = this.identifier;
 
 		if (window.initWeatherTheme) window.initWeatherTheme(this);