Expand align from l/c/r to a 3x3 grid with vertical prefixes:
tl/tc/tr/bl/bc/br. Vertical position renders via flex
justify-content; compact layers strings and YAML both parse the
new values, and the layer editor dropdown gains corner/edge
options.
Replace per-axis x1/y1/x2/y2 layer fields with a single
pos string (x1,y1-x2,y2) matching the compact layers format.
When a deck is configured via a yaml/tag codeblock (data-config),
the copy button now emits a yaml/tag block serialized from current
store state so template layers round-trip.
Allow md-deck layers to render markdown templates via {{var}}
substitution instead of only CSV props. Add config.ts to normalize
a JSON data-config attribute (size, grid, shape, layers) emitted by
the yaml code-block tag, taking precedence over legacy string props.
hypercross