feat: migrate to Vue 3.5 + Vite

Faithful 1:1 port of the single-file index.html to a Vite + Vue 3.5
project. All visuals, behavior, translations, quiz logic, scoring,
SVG paint filters, and modifier panel preserved. The previous
single-file build is archived as index.original.html for A/B compare.

Inline onclick handlers in the static template are converted to
Vue's @click bindings — Vue 3 ignores string-valued on* attributes,
which silently broke the qpb-logo "back to landing" navigation.
Inline handlers inside dynamically-injected innerHTML strings
(quiz options, slider, nav buttons) keep working since the browser
parses them; their target functions are exposed on window from
onMounted.

Pinned: vue 3.5.13, vite 6.4.2, @vitejs/plugin-vue 5.2.1.
Zero npm audit vulnerabilities.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,5 @@
+node_modules
+dist
+.DS_Store
+*.log
+.vite

package.json

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+{
+  "name": "kammergut",
+  "private": true,
+  "version": "0.1.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "vue": "3.5.13"
+  },
+  "devDependencies": {
+    "@vitejs/plugin-vue": "5.2.1",
+    "vite": "6.4.2"
+  }
+}

src/main.js

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+import { createApp } from 'vue'
+import App from './App.vue'
+import './styles.css'
+
+createApp(App).mount('#app')

vite.config.js

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+import { defineConfig } from 'vite'
+import vue from '@vitejs/plugin-vue'
+
+export default defineConfig({
+  plugins: [vue()],
+  server: { port: 5173 }
+})