Migrated all remaining legacy-alias consumers (incl. stories/tests) to --c-*
(199 refs / 58 files), promoted the computed aliases to first-class tokens
(--c-accent-fg made universal on :root; --c-primary-tint / --c-primary-border
added), then removed compat.css, its @import, and its linter entry. No legacy
colour-alias layer remains; build + theme-lint green.
The larger theme.css/tokens.css legacy definition files are a separate cleanup.
Static scanners (Aikido) flag the directory-listing→file-read flow as a
file-inclusion risk. Read a fixed THEME_FILES list via constant paths instead
(matching the other unflagged scripts); readdir is now only used to fail if a
new theme .css isn't registered, so coverage still can't lapse.