Release v4.187.1

Fixed

• A slice dialog asks for an identifier nothing supplies, such as the product a basket line names, instead of submitting without it. The identity the command itself acts on (its identifier) stays hidden and is created for the session. (part of #613)
• A screen keeps its session identities out of its own parameters, so a dialog no longer copies them into the address. (part of #613)
• A screen keeps its components' outputs while a dialog publishes its own. (part of #613)
• Commands from a Stage served under a path prefix (Studio Play) now go to that prefix even when no Arc base path is configured. Arc's default empty base path is treated as unset, and a configured base path still wins. (part of #618)