Kick and ban clients from the context menu

The client menu gains "Kick Client from Channel", "Kick Client from
Server" and "Ban Client", each asking for a reason first. Kicks use a
shared prompt that enforces the protocol's 40-character limit; the ban
dialog adds a duration, whose unit dropdown ends in "Permanent" — the
zero-length ban the server understands.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

ts3-client/swing/src/main/java/com/ts3client/ui/ServerTreePanel.java

@@ -47,6 +47,12 @@ public final class ServerTreePanel extends JScrollPane {
 
         void pokeClient(ClientEntry client);
 
+        void kickClientFromChannel(ClientEntry client);
+
+        void kickClientFromServer(ClientEntry client);
+
+        void banClient(ClientEntry client);
+
         void toggleClientMute(ClientEntry client);
 
         void showConnectionInfo(ClientEntry client);