feat: dashboard shows the live model version; DB stats count openmeteo_rain

The flood-outlook subtitle now reads '... · model hgb-v3+<sha> (trained
<date>)' from the forecast rows, so the deployed model is always visible
on the page. /api/stats adds openmeteo_rain_measurements (guarded — the
table may not exist on older DBs) to the whole-DB total, and the
Total-datapoints tile note gains a 'forecast rain' entry.

src/web_api.py

@@ -1222,6 +1222,22 @@ async def get_database_stats():
         except Exception as e:
             logger.warning(f"HII stats unavailable: {e}")
 
+        openmeteo_n = 0
+        try:  # table appears with the 2026-08 rain work; older DBs lack it
+            engine = _hii_engine()
+            if engine is not None:
+                from sqlalchemy import text as _text
+
+                with engine.connect() as conn:
+                    openmeteo_n = int(
+                        conn.execute(
+                            _text("SELECT COUNT(*) FROM openmeteo_rain")
+                        ).scalar()
+                        or 0
+                    )
+        except Exception:
+            pass
+
         def as_dt(value):
             if isinstance(value, str):
                 return datetime.fromisoformat(value)
@@ -1241,11 +1257,15 @@ async def get_database_stats():
                     last_ts = hi
 
         return {
-            # Whole-DB totals (RID + HII feeds); breakdown fields alongside
-            "total_measurements": stats["total_measurements"] + rain_n + wl_n,
+            # Whole-DB totals (RID + HII + Open-Meteo); breakdown alongside
+            "total_measurements": stats["total_measurements"]
+            + rain_n
+            + wl_n
+            + openmeteo_n,
             "rid_measurements": stats["total_measurements"],
             "hii_rainfall_measurements": rain_n,
             "hii_waterlevel_measurements": wl_n,
+            "openmeteo_rain_measurements": openmeteo_n,
             "station_count": stats["station_count"] + hii_stations,
             "rid_station_count": stats["station_count"],
             "hii_station_count": hii_stations,