chore: scaffold monorepo for EventSnap

- Rust/Axum backend skeleton with all crates, multi-stage Dockerfile
- SvelteKit + TypeScript frontend with Tailwind CSS v4, adapter-node, Dockerfile
- docker-compose.yml: db (postgres:16) → app → frontend → caddy with healthcheck and named volumes
- Caddyfile: TLS via Let's Encrypt, cache headers, API/media routing to backend
- .env.example: all environment variables documented with defaults
- README.md: project overview, features, stack, deploy guide, roadmap
- .gitignore: excludes secrets, build artifacts, node_modules, media uploads

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Caddyfile

@@ -0,0 +1,26 @@
+{$DOMAIN} {
+    encode zstd gzip
+
+    # SvelteKit frontend — static assets with long-lived cache (content-hashed filenames)
+    @hashed_assets path_regexp hashed /_app/immutable/.*\.[a-f0-9]{8,}\.(js|css|woff2)$
+    header @hashed_assets Cache-Control "public, max-age=31536000, immutable"
+
+    # Media previews and thumbnails
+    @previews path /media/previews/* /media/thumbnails/*
+    header @previews Cache-Control "public, max-age=3600"
+
+    # Original media files (private — only host can download)
+    @originals path /media/originals/*
+    header @originals Cache-Control "private, max-age=86400"
+
+    # API — never cache
+    @api path /api/*
+    header @api Cache-Control "no-store"
+
+    # Route API and media requests to the Rust backend
+    reverse_proxy /api/* app:3000
+    reverse_proxy /media/* app:3000
+
+    # Everything else goes to SvelteKit frontend
+    reverse_proxy frontend:3001
+}