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

frontend/src/components/LogoMark.vue

@@ -0,0 +1,22 @@
+<template>
+  <svg class="logo" viewBox="0 0 48 48" fill="none" xmlns="http://www.w3.org/2000/svg" aria-hidden="true">
+    <defs>
+      <linearGradient id="wp-lg" x1="0" y1="0" x2="1" y2="1">
+        <stop offset="0" stop-color="#7db0ff" />
+        <stop offset="1" stop-color="#b78cff" />
+      </linearGradient>
+    </defs>
+    <rect x="4.75" y="6.75" width="38.5" height="36.5" rx="10.5" fill="rgba(255,255,255,0.06)" stroke="url(#wp-lg)" stroke-width="2.2" />
+    <path d="M5 16h38" stroke="url(#wp-lg)" stroke-width="2.2" opacity="0.7" />
+    <path d="M15 3.5v6M33 3.5v6" stroke="url(#wp-lg)" stroke-width="3" stroke-linecap="round" />
+    <path d="M15 27l6.5 6.5L33.5 21" stroke="url(#wp-lg)" stroke-width="3.6" stroke-linecap="round" stroke-linejoin="round" />
+  </svg>
+</template>
+
+<style scoped>
+.logo {
+  width: 34px;
+  height: 34px;
+  filter: drop-shadow(0 4px 14px rgba(125, 176, 255, 0.35));
+}
+</style>