v0.6.3

• mcp/registry (fix): a free-form argument a server names in Config.ShownArguments is written as sent only for a call the tool answered. A call the tool failed, or one refused before it ran, was written the same way, though it was never held to the tool's own list of names: a setting the tool would not take, one that carries every signing key's secret, went into the line in clear. Such a call is now written with every value under the argument blanked, like any other
• mcp/registry: Config.LogWrite's doc says the line is not shown at a tool's default log level: it goes to the shared log at info, for whoever sets the log to info
• mcp/acctest: Suite.Secret's doc says a secret must be a string that is nothing's name and too long to turn up by chance; a password that is also a token's name is found wherever the name is listed