Add deterministic weather fallback

Scripts/verify_deterministic_weather_fallback.py

@@ -0,0 +1,51 @@
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+HEADER = ROOT / "Source" / "AgrarianGame" / "AgrarianWeatherProviderSubsystem.h"
+CPP = ROOT / "Source" / "AgrarianGame" / "AgrarianWeatherProviderSubsystem.cpp"
+TDD = ROOT / "Docs" / "TechnicalDesignDocument.md"
+ROADMAP = ROOT / "AGRARIAN_DEVELOPMENT_ROADMAP.md"
+
+
+EXPECTED = {
+    HEADER: [
+        "bEnableDeterministicFallbackWeather",
+        "ApplyDeterministicFallbackWeather",
+        "BuildDeterministicFallbackSnapshot",
+        "GetDeterministicWeatherNoise",
+    ],
+    CPP: [
+        "return ApplyDeterministicFallbackWeather(TileId, Latitude, Longitude, GameState);",
+        "Provider = TEXT(\"deterministic-fallback\")",
+        "GetDeterministicWeatherNoise(TileId, SafeDay",
+        "Snapshot.PrecipitationMm",
+        "Snapshot.VisibilityMeters",
+        "CacheSnapshot(Snapshot, WeatherSnapshotCacheTtlSeconds);",
+        "ApplyDeterministicFallbackWeather(TileId, Latitude, Longitude",
+    ],
+    TDD: [
+        "Deterministic fallback weather",
+        "tile ID and Agrarian day",
+        "provider `deterministic-fallback`",
+    ],
+    ROADMAP: [
+        "[x] Add deterministic fallback weather simulation when external weather data is unavailable.",
+    ],
+}
+
+
+def main() -> None:
+    missing = []
+    for path, snippets in EXPECTED.items():
+        text = path.read_text(encoding="utf-8")
+        for snippet in snippets:
+            if snippet not in text:
+                missing.append(f"{path.relative_to(ROOT)}: {snippet}")
+    if missing:
+        raise RuntimeError("Deterministic weather fallback verification failed: " + "; ".join(missing))
+    print("Agrarian deterministic weather fallback verification complete.")
+
+
+if __name__ == "__main__":
+    main()