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

server/2015Remote/lang/de_DE.ini

@@ -306,6 +306,7 @@ Web
 ; ============================================
 发送消息=Nachricht senden
 结束交谈=Chat beenden
+确定开始远程交谈吗?=Remote-Chat starten?
 锁定屏幕\n屏蔽功能键=Bildschirm sperren\nTasten blockieren
 解除锁定=Entsperren