update for 4 hour rain forecast

db/init/003_rain_predictions_4h.sql

@@ -0,0 +1,29 @@
+-- Add 4-hour rain prediction storage table.
+-- Safe to re-run.
+
+CREATE TABLE IF NOT EXISTS predictions_rain_4h (
+  ts                    TIMESTAMPTZ NOT NULL,
+  generated_at          TIMESTAMPTZ NOT NULL DEFAULT now(),
+  site                  TEXT NOT NULL,
+  model_name            TEXT NOT NULL,
+  model_version         TEXT NOT NULL,
+  threshold             DOUBLE PRECISION NOT NULL,
+  probability           DOUBLE PRECISION NOT NULL,
+  predict_rain          BOOLEAN NOT NULL,
+
+  rain_next_4h_mm_actual DOUBLE PRECISION,
+  rain_next_4h_actual    BOOLEAN,
+  evaluated_at           TIMESTAMPTZ,
+
+  metadata              JSONB,
+
+  PRIMARY KEY (site, model_name, model_version, ts)
+);
+
+SELECT create_hypertable('predictions_rain_4h', 'ts', if_not_exists => TRUE);
+
+CREATE INDEX IF NOT EXISTS idx_predictions_rain_4h_site_ts
+  ON predictions_rain_4h(site, ts DESC);
+
+CREATE INDEX IF NOT EXISTS idx_predictions_rain_4h_pending_eval
+  ON predictions_rain_4h(site, evaluated_at, ts DESC);