feat: wire remote-desktop plugin into core and rename i18n keys

Repoints core consumers (dispatcher, collab, session-sharing, tab
utils) at the plugin, adds isTabTypeAvailable gating for rdp/vnc/
telnet, widens hostCapability to accept an array, and renames the
guacamole i18n namespace to remoteDesktop.

src/ui/sidebar/HostEditorGeneralTab.tsx

@@ -773,7 +773,7 @@ export function HostEditorGeneralTab({
                 protocols.enableRdp ||
                 protocols.enableVnc ||
                 protocols.enableTelnet
-                  ? `${t("hosts.connectionOriginDesc")} ${t("hosts.connectionOriginGuacamoleNote")}`
+                  ? `${t("hosts.connectionOriginDesc")} ${t("hosts.connectionOriginRemoteDesktopNote")}`
                   : t("hosts.connectionOriginDesc")
               }
             >