max / quasi

Let a setting settle its argument, and a select mark its own options A slot that takes a structure has settings of its own, and until now there was nowhere to say them. `option Choice::new(id, name) { chosen when row.selected; }` is a setting with a body: the argument is built into a binding, the body's settings accrete onto it under their own guards, and the binding is what the container is handed. Written as a body rather than as a trailing word so the existing guard machinery reads it, and so a second setting on the same argument needs no new production. What it buys first is the theme picker. A select carried one value and the renderer decided which option was selected by comparing it against each, which a residual cannot hold: one compiled body per loop, and "exactly one row differs" is not a property of the body when the difference is a comparison the body does not make. Said per option it is a branch inside the row, and MNW's `/dashboard/tabs/ssh-keys` derives. A field says `chosen` or it says `value`, never both. Two ways to say one thing is how they drift and no renderer can tell them apart, so it is a compile error here, with a UI test on the message. Also lands the groundwork the described pager needs and cannot yet use (quasicoherent cbb63155, blocked on a look decision): a numeric stand-in, since a `usize` slot has no sentinel and a pager is three of them; slot direction for which arguments count rather than read; loops inside a setting's body; and a refusal for a pager written out of the order it draws in. quasicoherent c32bb877.