[Variant] Annan shogi（安南将棋）

[ghost]

Same board size and pieces as standard shogi
Popular in Japan and has a long history
Very deep gameplay
Annanshogi has not been implemented on other sites.

https://en.wikipedia.org/wiki/Annan_shogi

[WandererXII]

Wikipedia article mentions there are two variants:

when a piece has a friendly piece on the square directly behind it, it has the movement of that piece instead of its own

and

piece may move like any friendly piece that protects it

I suppose we want to go with the first main(?) one?

[WandererXII]

Here's a demo: https://lishogi1.org/assets/sandbox/annan/index.html

If anyone's familiar with annan shogi, please look it over.