Persist applied weather debug state

Docs/TechnicalDesignDocument.md

@@ -183,13 +183,22 @@ They receive weather, temperature, source, and state through replicated game
 state fields.
 
 Real-weather provider values are mapped into `FAgrarianMappedWeatherInputs`
-before they affect gameplay. The mapped snapshot keeps temperature,
+before they affect gameplay. The mapped snapshot keeps tile ID, tile center
+coordinate, temperature,
 precipitation, wind, cloud cover, humidity, pressure, visibility, and provider
 weather code available alongside the collapsed Agrarian weather state. Open-Meteo
 fills those fields directly where available; NOAA/NWS fills them from grid data
 where available and derives provisional visibility/weather-state values until a
 deeper provider-specific mapping pass is added.
 
+The applied weather state also has a replicated debug snapshot:
+`FAgrarianWeatherDebugSnapshot`. It records the weather source, provider
+timestamp, tile ID, tile center coordinate, provider weather code, input values,
+and final in-game `EAgrarianWeatherType` after mapping. Save files persist both
+the mapped inputs and the applied debug snapshot so weather issues can be traced
+back to a specific provider response and tile without inferring those values from
+separate systems.
+
 Deterministic fallback weather keeps the game playable when external providers
 are disabled, unreachable, or return unusable data. The fallback snapshot is
 derived from tile ID and Agrarian day, then mapped through the same