Use Storybook's useArgs hook from storybook/preview-api to update
args from within the render function. This wires fn() callbacks to
the Actions panel AND updates the UI state through Storybook's args
system. All form interactions (add/remove/edit headers/metadata,
accordion open/close, connection mode, timeouts, OAuth) now both
update the UI and log to the Actions panel.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>