Kill-All Go: on-board pickers, 13x13 default, no passing

[samtcifihi]

Handicap opening: the handicap is chosen by clicking a numbered stone. 1 to 18 sit in two centred rows of nine, the odd values on the row just above the centre point and the even values on the row just below it. Larger handicaps can still be entered manually, up to floor(p/2).

Generalized Hoctaph's pie: the two batch sizes are chosen by clicking numbered stones. Each batch offers 1 to ceil(2p/25) (7, 14 and 29 on 9x9, 13x13 and 19x19). The first batch sits above the centre point and the second is mirrored below it, with three empty rows between them. Each block starts with a centred row of up to nine values and then snakes away from the centre. A value that the other batch's size rules out is faded but stays clickable; choosing it drops that other size. Larger sizes can still be entered manually, within the real limits.

In both pickers the chosen value gets an enter annotation. Clicking anywhere else gives a short warning naming the point, as invalid clicks do in other games.

13x13 is now preselected when issuing a challenge (default: true on size-13). No variant IDs change, and a game without a board variant is still 19x19, so existing games are unaffected.

Passing is no longer allowed once the opening is over. Normal play has no pass button, pass is not a legal move, and a pass is rejected, so a game can no longer end with two passes in a row. Passing to place no stones in the simple pie still works. A game that already ended with two passes still shows that result in its log.

Messages: the description, variant descriptions and in-game prompts now describe the goal as unconditional life. The implementation notes cover pass-alive strings (Benson's algorithm; seki and ko do not count), the rule against passing after the opening, Tromp-Taylor clearing (multi-stone suicide is legal) and positional superko. The Hoctaph prompt explains the order the batches are placed in and leaves each limit to its own error. Messages that spoke of typing now speak of click entry. English and Esperanto.