Add app pairing feature for simplified registry connection

- Add pairing_requests table and hostname column to api_tokens
- Add pairing API endpoints: initiate, check, status, connected-apps
- Add cmdforge config connect <username> CLI command
- Rewrite tokens.html as Connected Apps with pairing flow
- Update TUI: Connect button when not authenticated, Publish when connected
- Add private sync option after save in TUI when connected
- Add visibility parameter to publish_tool in registry_client

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

src/cmdforge/cli/__init__.py

@@ -240,6 +240,11 @@ def main():
     p_cfg_set.add_argument("value", help="Config value")
     p_cfg_set.set_defaults(func=cmd_config)
 
+    # config connect
+    p_cfg_connect = config_sub.add_parser("connect", help="Connect this app to your CmdForge account")
+    p_cfg_connect.add_argument("username", help="Your CmdForge username")
+    p_cfg_connect.set_defaults(func=cmd_config)
+
     # Default for config with no subcommand
     p_config.set_defaults(func=lambda args: cmd_config(args) if args.config_cmd else (setattr(args, 'config_cmd', 'show') or cmd_config(args)))