[verified] feat: add live river dashboard

Add mapped river and ThaiWater sensor layers, PostgreSQL history charts, API endpoints, and dashboard tests.

tests/test_postgres_history.py

@@ -0,0 +1,49 @@
+import datetime
+
+from sqlalchemy import create_engine, text
+
+from src.postgres_history import PostgresHistory
+
+
+def test_history_returns_station_series_in_chronological_order(tmp_path):
+    engine = create_engine(f"sqlite:///{tmp_path / 'history.db'}")
+    with engine.begin() as connection:
+        connection.execute(text("CREATE TABLE stations (id INTEGER PRIMARY KEY, station_code TEXT)"))
+        connection.execute(
+            text(
+                "CREATE TABLE water_measurements ("
+                "timestamp DATETIME, station_id INTEGER, water_level REAL, "
+                "discharge REAL, discharge_percent REAL)"
+            )
+        )
+        connection.execute(text("INSERT INTO stations VALUES (1, 'P.1'), (2, 'P.20')"))
+        connection.execute(
+            text(
+                "INSERT INTO water_measurements VALUES "
+                "('2026-08-09 13:00:00', 1, 3.2, 110.0, 40.0),"
+                "('2026-08-09 14:00:00', 1, 3.4, 120.0, 42.0),"
+                "('2026-08-09 14:00:00', 2, 2.1, 30.0, 15.0)"
+            )
+        )
+
+    history = PostgresHistory(engine=engine).station_history(
+        "P.1",
+        start=datetime.datetime(2026, 8, 9, 12),
+        end=datetime.datetime(2026, 8, 9, 15),
+        limit=100,
+    )
+
+    assert [row["timestamp"].hour for row in history] == [13, 14]
+    assert [row["discharge"] for row in history] == [110.0, 120.0]
+    assert all(row["station_code"] == "P.1" for row in history)
+
+
+def test_history_rejects_excessive_limit():
+    history = PostgresHistory.__new__(PostgresHistory)
+
+    try:
+        history.station_history("P.1", datetime.datetime.now(), datetime.datetime.now(), 5001)
+    except ValueError as error:
+        assert "limit" in str(error)
+    else:
+        raise AssertionError("Expected excessive history limit to be rejected")