Add Silo auth dock widget, update silo submodule

Wire up the new Silo authentication dock panel in InitGui.py:
- _setup_silo_auth_panel() creates the Database Auth dock widget
- Tabified with the existing Database Activity panel on the right dock
- Deferred to 4500ms to ensure activity panel exists first
- Widget reference pinned on the dock panel to prevent GC

Update silo submodule to include auth widget, login flow, token
management, enhanced settings dialog, and silo-auth.svg icon.

src/Mod/Create/InitGui.py

@@ -140,6 +140,41 @@ def _setup_silo_activity_panel():
         FreeCAD.Console.PrintLog(f"Create: Silo activity panel skipped: {e}\n")
 
 
+def _setup_silo_auth_panel():
+    """Show a dock widget with Silo authentication status and login."""
+    try:
+        from PySide import QtCore, QtWidgets
+
+        mw = FreeCADGui.getMainWindow()
+        if mw is None:
+            return
+
+        # Don't create duplicate panels
+        if mw.findChild(QtWidgets.QDockWidget, "SiloDatabaseAuth"):
+            return
+
+        panel = QtWidgets.QDockWidget("Database Auth", mw)
+        panel.setObjectName("SiloDatabaseAuth")
+
+        import silo_commands
+
+        auth_widget = silo_commands.SiloAuthDockWidget()
+        panel.setWidget(auth_widget.widget)
+        # Keep a reference so the timer and callbacks are not garbage-collected
+        panel._auth_widget = auth_widget
+
+        mw.addDockWidget(QtCore.Qt.RightDockWidgetArea, panel)
+
+        # Tabify with the activity panel so they share the same dock area
+        activity_panel = mw.findChild(QtWidgets.QDockWidget, "SiloDatabaseActivity")
+        if activity_panel:
+            mw.tabifyDockWidget(activity_panel, panel)
+            panel.raise_()
+
+    except Exception as e:
+        FreeCAD.Console.PrintLog(f"Create: Silo auth panel skipped: {e}\n")
+
+
 # Defer enhancements until the GUI event loop is running
 try:
     from PySide.QtCore import QTimer
@@ -147,5 +182,6 @@ try:
     QTimer.singleShot(2000, _setup_silo_menu)
     QTimer.singleShot(3000, _check_silo_first_start)
     QTimer.singleShot(4000, _setup_silo_activity_panel)
+    QTimer.singleShot(4500, _setup_silo_auth_panel)
 except Exception:
     pass