feat(ui): add wedding theme styles and layout components

* Introduced wedding-themed CSS variables for styling.
* Created layout component for the wedding site with navigation and countdown.
* Added RSVP and photo upload pages with form handling.
* Implemented QR code page for wedding site access.
* Configured TypeScript and Vite for the project.
* Added robots.txt for search engine crawling.

.dockerignore

@@ -0,0 +1,7 @@
+data/
+config.yaml
+ui/node_modules
+ui/build
+ui/.svelte-kit
+server/wedding-server
+.git