Add disconnect command and fix GUI connection status refresh

- Add `cmdforge config disconnect` command to clear registry token
- Fix GUI connection status label not updating after connect
  - Store status as instance variable instead of local
  - Add _update_connection_status() method
  - Call update after connect dialog completes

Co-Authored-By: Claude Opus 4.5 <[email protected]>

src/cmdforge/gui/pages/tools_page.py

@@ -83,14 +83,9 @@ class ToolsPage(QWidget):
         header_layout.addStretch()
 
         # Connection status
-        config = load_config()
-        if config.registry.token:
-            status = QLabel("Connected to Registry")
-            status.setStyleSheet("color: #38a169; font-weight: 500;")
-        else:
-            status = QLabel("Not connected")
-            status.setStyleSheet("color: #718096;")
-        header_layout.addWidget(status)
+        self.connection_status = QLabel()
+        self._update_connection_status()
+        header_layout.addWidget(self.connection_status)
 
         layout.addWidget(header)
 
@@ -174,6 +169,16 @@ class ToolsPage(QWidget):
 
         layout.addWidget(buttons)
 
+    def _update_connection_status(self):
+        """Update the connection status label."""
+        config = load_config()
+        if config.registry.token:
+            self.connection_status.setText("Connected to Registry")
+            self.connection_status.setStyleSheet("color: #38a169; font-weight: 500;")
+        else:
+            self.connection_status.setText("Not connected")
+            self.connection_status.setStyleSheet("color: #718096;")
+
     def refresh(self):
         """Refresh the tool list."""
         self.tool_tree.clear()
@@ -392,6 +397,7 @@ class ToolsPage(QWidget):
         dialog = ConnectDialog(self)
         if dialog.exec():
             self.refresh()
+            self._update_connection_status()
             self.main_window.show_status("Connected to registry")
             # Recreate publish button
             self.btn_publish.setText("Publish")