The plugin text API rejected negative letter-spacing even though the
product UI allows -200..200 (typography.cljs). Two defects in
frontend/src/app/plugins/text.cljs:
- `letter-spacing-re` (`#"^\d*\.?\d*$"`) had no provision for a leading
minus, so any negative value failed validation.
- The text-range `:letterSpacing` setter inverted its guard: it used
`(or (empty? value) (re-matches ...))` to mean "invalid", which
rejected matching values and let non-numeric input through. The
text-shape setter and the sibling `lineHeight` range setter both
correctly use `(not (re-matches ...))`.
Fix the regex to allow an optional leading minus and add the missing
`not` so the range setter matches the shape setter. Adds regression
coverage for the regex accept/reject contract.
Fixes#9780
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Signed-off-by: Filip Sajdak <filip.sajdak@siili.com>
