const BUBBLE_POSITION_FORMAT_VERSION: &str = "v2";Expand description
Persistence file-format version prefix. Bumping this string causes
decode_position to reject any file written by an earlier version,
which falls through to compute_default_position and re-applies the
current default-corner rule (M-BUBBLE.3 originally shipped
bottom-right; the design pass moved the default to bottom-left, and
stale v1 files were keeping the bubble in the old corner).