修复机场高频推送：东京ICAO不匹配、釜山缺趋势数据、港/流浮频率及obs_time去重

- 东京 HIGH_FREQ_AIRPORT_ICAO 从 RJTT 改为 JMA 站号 44166
- 釜山 METAR 集群数据写入 airport_obs_log 供趋势检测
- 香港/流浮山推送间隔从 60s 改为 600s（匹配实际 10min 更新）
- 新增 obs_time 去重：同一观测数据不重复推送

Constraint: JMA AMeDAS 使用站号而非 ICAO 作为站点标识
Tested: ruff check 通过

src/data_collection/metar_sources.py

@@ -453,6 +453,7 @@ class MetarSourceMixin:
                             "lat": lat,
                             "lon": lon,
                             "temp": round(display_temp, 1),
+                            "temp_c": temp_c,
                             "istNo": icao,
                             "icao": icao,
                             "wind_dir": obs.get("wdir"),

src/data_collection/weather_sources.py

@@ -866,6 +866,23 @@ class WeatherDataCollector(OpenMeteoCacheMixin, SettlementSourceMixin, MetarSour
         if cluster_data:
             results["mgm_nearby"] = cluster_data
             results["nearby_source"] = "metar_cluster"
+            # 写入 airport_obs_log，供高频推送的趋势检测使用
+            try:
+                from src.database.db_manager import DBManager
+                db = DBManager()
+                for row in cluster_data:
+                    icao = row.get("icao")
+                    temp_c = row.get("temp_c") if "temp_c" in row else row.get("temp")
+                    if icao and temp_c is not None:
+                        db.append_airport_obs(
+                            icao=str(icao),
+                            city=city_lower,
+                            temp_c=temp_c,
+                            wind_kt=row.get("wind_speed_kt"),
+                            obs_time=str(row.get("obs_time") or datetime.now().isoformat()),
+                        )
+            except Exception:
+                logger.exception("airport_obs_log append failed for metar cluster city={}", city_lower)
 
     def _attach_china_official_nearby(
         self, results: Dict, city_lower: str, use_fahrenheit: bool