Simplify coordinate lookup: remove proxy support

Free proxies from proxifly/free-proxy-list don't support HTTPS well
and are unreliable. Stick with cache + concurrent approach.

- Remove proxy fetching and handling code
- Default workers reduced to 2 to be more conservative
- Rely on persistent cache for efficiency

Usage: Run in small batches to avoid Nominatim rate limits.
Once cached, results are instant.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cpc_direct_stations.py

@@ -190,7 +190,7 @@ def geocode(address: str, station_name: str, city: str, district: str) -> Option
             }
             url = f"https://nominatim.openstreetmap.org/search?{urllib.parse.urlencode(params)}"
             req = urllib.request.Request(url, headers={"User-Agent": user_agent})
-            with urllib.request.urlopen(req, timeout=10) as response:
+            with urllib.request.urlopen(req, timeout=15) as response:
                 data = json.loads(response.read().decode("utf-8"))
                 if data:
                     return {"lat": float(data[0]["lat"]), "lon": float(data[0]["lon"])}
@@ -199,13 +199,13 @@ def geocode(address: str, station_name: str, city: str, district: str) -> Option
     return None
 
 
-def add_coordinates(stations: List[Dict[str, str]], delay: float = 1.0, workers: int = 3) -> List[Dict[str, str]]:
+def add_coordinates(stations: List[Dict[str, str]], delay: float = 1.0, workers: int = 2) -> List[Dict[str, str]]:
     """為站點資料加上座標資訊（使用快取+並發查詢）。
 
     Args:
         stations: 站點列表
         delay: 每個查詢間隔秒數（Nominatim 限制約 1 秒）
-        workers: 並發查詢執行緒數（預設 3，Nominatim 免費版限制）
+        workers: 並發查詢執行緒數（預設 2，避免 Nominatim 限制）
     """
     cache = load_coords_cache()
     missing_coords = []
@@ -377,7 +377,7 @@ def main() -> None:
     parser.add_argument("--out", help="輸出到檔案路徑")
     parser.add_argument("--coords", action="store_true", help="加上座標資訊（使用 Nominatim OSM API）")
     parser.add_argument("--delay", type=float, default=1.0, help="座標查詢間隔秒數（預設 1.0）")
-    parser.add_argument("--workers", type=int, default=3, help="並發查詢執行緒數（預設 3）")
+    parser.add_argument("--workers", type=int, default=2, help="並發查詢執行緒數（預設 2，避免 Nominatim 限制）")
     args = parser.parse_args()
 
     html = build_query_html(city=args.city, keyword=args.keyword)