cairn/changes/first-run-wizard-frame/delta.md
A configure command (alias wizard) SHALL run the wizard by name, without the welcome, since whoever typed it knows what it does. It refuses to run when stdin is not a terminal, naming the sample configuration to write by hand instead.
A missing configuration SHALL raise an offer to generate one, from a bare invocation and from any command needing an account. The offer never ends the process: a command carries on afterwards either way, so accepting gives it a chance to work and declining leaves it to fail on the configuration it still has not got. A bare invocation has nothing to carry on to, so a declined offer falls back to the help. Nothing is offered when stdin is not a terminal or --json is set.
The welcome SHALL name the configuration path that was looked for, which is the one -c or HIMALAYA_CONFIG gave or the default location, so a mistyped path shows up as itself rather than as a generic first run. It frames the product, points at the documented sample, and names the command that runs the wizard again later.
The wizard SHALL write a configuration file that does not exist and append a plain text block to one that does, never parsing and re-serializing the document, so comments, ordering and formatting survive. Two invariants guard the append: the account name must be free, since a second [accounts.<name>] table makes the whole document fail to parse, and the generated account claims default only when no other account does. The derived name is suffixed until free. The target path is not prompted: it is where -c pointed, or the default location.
The serializer SHALL decide what a generated account holds, so a defaulted field is omitted and no field is enumerated twice, but the rendering SHALL order what it emits: the groups run most-defining first (default, the storage backend, the transport, the mailboxes, the rendering options), an unrecognised group renders after them rather than being dropped, a group's server key reads before the credentials qualifying it, and a blank line separates groups.
Each of the three ways account resolution fails SHALL name what is missing and what to do about it: a missing configuration names the path it looked for, a missing named account lists the accounts the configuration does hold, and a missing default names both ways of picking one.
The wizard no longer asks where to save. The path comes from -c, HIMALAYA_CONFIG or the default location, and an existing file is appended to rather than overwritten, so the overwrite confirmation goes with it.