feat: add WannPassts booking app with Go backend and Vue frontend

Initial project setup for a privacy-focused, self-hosted scheduling app:

- Go backend with JWT auth, SQLite storage, and chi router
- Calendar integrations via Google OAuth (FreeBusy), CalDAV, and ICS links
- Public booking pages with configurable slots and booking requests
- AES-256-GCM encryption for stored provider tokens
- Vue 3 + TypeScript frontend with Vite, Pinia, and Vue Router
- Docs, .gitignore, and .env.example for local development

backend/go.mod

@@ -0,0 +1,29 @@
+module wannpassts
+
+go 1.25.0
+
+require (
+	github.com/emersion/go-ical v0.0.0-20250609112844-439c63cef608
+	github.com/emersion/go-webdav v0.7.0
+	github.com/go-chi/chi/v5 v5.3.2
+	github.com/go-chi/cors v1.2.2
+	github.com/golang-jwt/jwt/v5 v5.3.1
+	github.com/joho/godotenv v1.5.1
+	golang.org/x/crypto v0.55.0
+	golang.org/x/oauth2 v0.36.0
+	modernc.org/sqlite v1.57.0
+)
+
+require (
+	cloud.google.com/go/compute/metadata v0.3.0 // indirect
+	github.com/dustin/go-humanize v1.0.1 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/mattn/go-isatty v0.0.24 // indirect
+	github.com/ncruces/go-strftime v1.0.0 // indirect
+	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
+	github.com/teambition/rrule-go v1.8.2 // indirect
+	golang.org/x/sys v0.47.0 // indirect
+	modernc.org/libc v1.74.4 // indirect
+	modernc.org/mathutil v1.7.1 // indirect
+	modernc.org/memory v1.11.0 // indirect
+)