Send a message to the setup advisor; while quoted, this may replace the quote

Sends a message to the setup advisor. While the order is quoted, a new message can trigger a fresh advisor turn that replaces the quote - unless a checkout is currently open for it (checkout_open), which freezes the quote until that Checkout session expires or is used. On other statuses (ready, paid, building, revision), the message is simply recorded for the volai team; sending it while ready moves the order to revision. Rounds included in the package (order.quote.revisionsIncluded, already used order.revisionsUsed) are free; once they are used up, the next round the founder finishes is charged 490 CZK excl. VAT from credit as a setup_revision ledger entry.