A Playground under each project: send a request from the console and read its receipt

Playground, next to Dispatch and Logs, sends a chat, Messages, Responses, embeddings or images request as one of the project's keys and shows the streamed answer with its receipt beside it: the model and provider that served it, every upstream call and the routes skipped, time to first token, tokens and the charge, with a link to the request in Logs. Only models and aliases the project's Directives allow are offered, so a denial is explained where the Directive lives.