Redo katmos a bit

[jupyterkat]

now it knows it's already in a floodfilled area

• vishashes is now stored as an atomic inside TurfMixture
• vishashes now represent vis updates more accurately, reducing unecessary updates by alot
• no more scc, back to the old par iter
• turfarena is back to using stablegraph, for less itering?????, less memory usage???
• turfarena map is now an indexmap, because that's faster for some reason