› empty, loading, error

rules

• A control that needs background work (a captcha, the session, a socket, a lazy chunk) is either disabled with a visible reason or enabled with a queue that finishes the action once ready. It is never enabled and then refused.
• Every wait has a visible state, a timeout, a plain error, and a way to retry or recover.
• No failure is silent: it's shown, or deliberately ignored with a comment in the code.
• Actions are idempotent where they can be: double submits are blocked and sends carry a client id.
• State is checked again on return: back/forward and the back-forward cache, tab visibility and reconnects.
• Unknown is not down: when a check can't get an answer, say it's unknown.

specimens