Two columns (form left, preview right, matching D9) with a mini mock of this
app's own sidebar + a sample button -- primary_color/secondary_color are
what those actually control (base.html's --tenant-* properties), so the
preview reflects a real surface rather than D9's aspirational App/Website/
Email tabs. Colour swatch pickers sync with the existing hex text fields in
both directions, and a contrast-ratio row mirrors Club._content_color_for's
exact WCAG math client-side, so the ✓/⚠ shown is the real number the server
computes on save.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ECGMEwrc2k4D8VQuwjstj9
Bernard Siebens
fc3901fb5a