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>

.env.example

@@ -0,0 +1,45 @@
+# ── Domain ────────────────────────────────────────────────────────────────────
+# Public domain Caddy will serve and obtain a TLS certificate for.
+DOMAIN=my-event.example.com
+
+# ── App server ────────────────────────────────────────────────────────────────
+APP_PORT=3000
+
+# ── Database ──────────────────────────────────────────────────────────────────
+DATABASE_URL=postgres://eventsnap:secret@db:5432/eventsnap
+POSTGRES_USER=eventsnap
+POSTGRES_PASSWORD=secret
+POSTGRES_DB=eventsnap
+
+# ── Authentication ────────────────────────────────────────────────────────────
+# Generate with: openssl rand -hex 64
+JWT_SECRET=change_me_to_a_random_64_byte_hex_string
+SESSION_EXPIRY_DAYS=30
+
+# Admin dashboard password (bcrypt hash).
+# Generate with: htpasswd -bnBC 12 "" yourpassword | tr -d ':\n'
+ADMIN_PASSWORD_HASH=$2y$12$placeholder_replace_me
+
+# ── Event ─────────────────────────────────────────────────────────────────────
+EVENT_NAME=Max & Maria's Wedding
+EVENT_SLUG=max-maria-2026
+
+# ── Storage ───────────────────────────────────────────────────────────────────
+MEDIA_PATH=/media
+
+# ── Upload limits ─────────────────────────────────────────────────────────────
+DEFAULT_MAX_IMAGE_SIZE_MB=20
+DEFAULT_MAX_VIDEO_SIZE_MB=500
+
+# ── Rate limiting ─────────────────────────────────────────────────────────────
+DEFAULT_UPLOAD_RATE_PER_HOUR=10
+DEFAULT_FEED_RATE_PER_MIN=60
+DEFAULT_EXPORT_RATE_PER_DAY=3
+
+# ── Capacity ──────────────────────────────────────────────────────────────────
+DEFAULT_ESTIMATED_GUEST_COUNT=100
+# Fraction of total storage that triggers the "low storage" warning (0.0–1.0)
+DEFAULT_QUOTA_TOLERANCE=0.75
+
+# ── Workers ───────────────────────────────────────────────────────────────────
+COMPRESSION_WORKER_CONCURRENCY=2