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/ShareLinkCard.vue

@@ -0,0 +1,46 @@
+<script setup lang="ts">
+import { computed, ref } from 'vue'
+import { useAuth } from '../stores/auth'
+import { useToast } from '../stores/toast'
+import GlassCard from './GlassCard.vue'
+
+const auth = useAuth()
+const toast = useToast()
+const copied = ref(false)
+
+const link = computed(() => `${location.origin}/b/${auth.user?.slug ?? ''}`)
+
+async function copy() {
+  try {
+    await navigator.clipboard.writeText(link.value)
+    copied.value = true
+    toast.ok('Link kopiert!')
+    setTimeout(() => (copied.value = false), 2000)
+  } catch {
+    toast.error('Kopieren nicht möglich – bitte manuell markieren.')
+  }
+}
+</script>
+
+<template>
+  <GlassCard title="🔗 Dein Buchungslink" subtitle="Teile diesen Link – andere sehen nur frei/belegt und können anfragen.">
+    <div class="row link-row">
+      <code class="link glass-soft grow">{{ link }}</code>
+      <button class="btn btn-primary" @click="copy">{{ copied ? 'Kopiert ✓' : 'Kopieren' }}</button>
+    </div>
+    <p class="faint small" style="margin: 0">
+      Tipp: QR-Code oder Link in Signatur, Website oder Nachrichtenaustausch einbauen.
+    </p>
+  </GlassCard>
+</template>
+
+<style scoped>
+.link-row { flex-wrap: wrap; }
+.link {
+  padding: 12px 16px;
+  font-size: 14px;
+  overflow-x: auto;
+  white-space: nowrap;
+  color: var(--accent);
+}
+</style>