Fix: Decode geographic location as UTF-8 across client and server

Geographic location (city, country) from the geo APIs is UTF-8, but the client
and several server paths converted or stored it in the system ANSI code page,
turning umlauts ("ö"/"ä") into "?" or GBK mojibake ("B枚blingen"). Keep the
value UTF-8 end to end: the client caches it as UTF-8 and re-queries once after
an upgrade (keyed by __DATE__, the app's version convention), while the server
stores and displays it as UTF-8 in the online list, the activity log, the
client-info export, JSON/email payloads and search.

Also add a confirmation prompt before opening a remote chat from the toolbar,
with German, English and Traditional-Chinese translations.

Co-Authored-By: deepseek-v4-pro

client/LoginServer.cpp

@@ -378,13 +378,29 @@ LOGIN_INFOR GetLoginInfo(DWORD dwSpeed, CONNECT_ADDRESS& conn, const std::string
     std::string pubIP = cfg.GetStr("settings", "public_ip", "");
     auto ip_time = cfg.GetInt("settings", "ip_time");
     bool timeout = ip_time <= 0 || (time(0) - ip_time > 7 * 86400);
+    // 升级后强制重新查询一次：旧版缓存的 location 是 GBK/CP1252，或已把 ö/ä/ß 等替换成 '?'；
+    // 新版 GetGeoLocation 改为 UTF-8 上报（见 common/location.h），需重新拉取才能修正。
+    // 版本号即编译日期 __DATE__（见 common/commands.h 的 DLL_VERSION）：编译期宏，内存 DLL
+    // 也能取到，且每次编译都会变，天然标识“升级”，无需手动递增，也不依赖 exe 版本资源。
+    bool cacheVerChanged = (cfg.GetStr("settings", "loc_cache_ver", "") != __DATE__);
     IPConverter cvt;
-    if (loc.empty() || pubIP.empty() || timeout) {
-        pubIP = cvt.getPublicIP();
-        loc = cvt.GetGeoLocation(pubIP);
-        cfg.SetStr("settings", "location", loc);
-        cfg.SetStr("settings", "public_ip", pubIP);
-        cfg.SetInt("settings", "ip_time", time(0));
+    if (loc.empty() || pubIP.empty() || timeout || cacheVerChanged) {
+        std::string newPubIP = pubIP;
+        // 升级重查 location 时复用已缓存的公网 IP；仅当 IP 缺失或 7 天过期才重新探测，
+        // 否则离线/无外网机器每次重连都会轮询 5 个公网 IP 源、空等数秒到十几秒。
+        if (pubIP.empty() || timeout) {
+            newPubIP = cvt.getPublicIP();
+        }
+        std::string newLoc = cvt.GetGeoLocation(newPubIP);
+        // 仅查询成功才覆盖缓存并推进版本号；失败保留旧值，下次登录仍会重试。
+        if (!newLoc.empty() && !newPubIP.empty()) {
+            pubIP = newPubIP;
+            loc = newLoc;
+            cfg.SetStr("settings", "location", loc);
+            cfg.SetStr("settings", "public_ip", pubIP);
+            cfg.SetInt("settings", "ip_time", time(0));
+            cfg.SetStr("settings", "loc_cache_ver", __DATE__);
+        }
     }
     LoginInfor.AddReserved(loc.c_str());
     LoginInfor.AddReserved(pubIP.c_str());