将商业核心数据源 URL 从源码迁移到环境变量，VPS .env 已补全

.env.example

@@ -63,8 +63,22 @@ POLYWEATHER_METAR_TIMEOUT_SEC=4
 POLYWEATHER_METAR_CLUSTER_TIMEOUT_SEC=3.5
 METAR_CACHE_TTL_SEC=600
 JMA_AMEDAS_CACHE_TTL_SEC=120
-# Recommended on VPS: do not train there; pull the SQLite DB to a local machine.
-# Optional: set this to a writable runtime path if you manually deploy a
+
+# ── Country-specific data source URLs ──
+# These are kept in .env to avoid exposing competitive data-source discovery
+# work on the public GitHub repository. Leave empty to use built-in defaults.
+# AMSC_AWOS_BASE_URL=https://www.amsc.net.cn/gateway/api/saas/rest/amc/AwosController/getWindPlate
+# NMC_FORECAST_BASE_URL=https://m.nmc.cn/publish/forecast
+# NMC_REALTIME_BASE_URL=https://www.nmc.cn/rest/real
+# KMA_BASE_URL=https://www.weather.go.kr
+# AMOS_BASE_URL=https://global.amo.go.kr/amosobsnew/AmosRealTimeImage.do
+# JMA_AMEDAS_BASE_URL=https://www.jma.go.jp
+# MGM_BASE_URL=https://servis.mgm.gov.tr/web
+# MGM_ORIGIN_URL=https://www.mgm.gov.tr
+# FMI_BASE_URL=https://opendata.fmi.fi/wfs
+# HKO_BASE_URL=https://data.weather.gov.hk/weatherAPI/hko_data/regional-weather
+# SINGAPORE_MSS_BASE_URL=https://api.data.gov.sg/v1/environment/air-temperature
+# RUSSIA_POGODAIKLIMAT_BASE_URL=https://www.pogodaiklimat.ru
 
 ########################################
 # 4) Auth / entitlement