Extract mic/speaker/away/commander state handling into
ServerTabSelfState, ServerTreePanel.Actions delegation (context
menus, drag-drop, link clicks) into ServerTabTreeActions, and
ConnectionListener event marshaling onto the EDT into
ServerTabConnectionEvents. ServerTab keeps its full public API
(636 -> 377 lines); no behavior change.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
