feat: hourly HII/ThaiWater rainfall + backup water-level collection

Poll the open api-v3.thaiwater.net public endpoints (rain_24h,
waterlevel_load), filter to the Ping basin, and persist to new
hii_rain_stations/hii_rainfall and hii_wl_stations/hii_waterlevel tables
(auto-created; sqlite/postgresql/mysql). Water levels stay in their own
tables since HII reports m MSL from a different station set; rid_code
maps mirrors like ridhydro_P.1 to P.1 and offset_msl converts MSL to
gauge datum. Runs every scraping cycle in web-api and continuous modes
(hourly cadence even during 1-minute RID retry), one-shot via
--collect-hii; docs/DATA_SOURCES.md catalogs all probed endpoints.

docs/references/NOTABLE_DOCUMENTS.md

@@ -34,6 +34,20 @@ This document contains important references and external resources related to th
 - **Usage**: Reference for individual station characteristics and historical data patterns
 - **Station**: P.76 - บ้านแม่อีไฮ (Banb Mae I Hai)
 
+### **ThaiWater / HII (Hydro-Informatics Institute) Resources**
+
+#### **4. ThaiWater Portal**
+- **URL**: https://twa.thaiwater.net
+- **Description**: National water situation portal (rainfall, water level, dams, warnings)
+- **Language**: Thai/English
+- **Usage**: Backed by open and auth-gated APIs — full endpoint catalog in [DATA_SOURCES.md](../DATA_SOURCES.md)
+
+#### **5. ThaiWater Data Standard**
+- **URL**: https://standard.thaiwater.net
+- **Description**: Official water-data standard for exchange and warning — canonical station/basin/province code registries, data formats, warning-level definitions
+- **Language**: Thai
+- **Usage**: Reference for station metadata and warning-level semantics
+
 ## 📊 **Data Sources and APIs**
 
 ### **Primary Data Source**