014b4175b9
- Add /color-strip-sources/preview/ws endpoint for ad-hoc source preview
without saving (accepts full config JSON, streams RGB frames)
- Add test preview button (flask icon) to CSS editor modal footer
- For self-contained types (static, gradient, color_cycle, effect, daylight,
candlelight), always previews current form values via transient WS
- For non-previewable types, falls back to saved source test endpoint
- Fix route ordering: preview/ws registered before {source_id}/ws
- Fix css-test-led-control label alignment (display: inline globally)
- Add gradient onChange callback for future live-update support
- Add i18n keys for preview (en/ru/zh)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>