feat(astrolabe): upgrade to Vue 3 and @nextcloud/vue 9

- Merge renovate/major-vue-monorepo: Vue 2.7.16 → 3.5.26
- Merge renovate/nextcloud-vue-9.x: @nextcloud/vue 8.29.2 → 9.3.1
- Update component imports to new @nextcloud/vue v9 paths
- Replace .sync modifiers with v-model:prop (Vue 3 syntax)
- Replace beforeDestroy with beforeUnmount lifecycle hook
- Remove Vue.() usage (automatic reactivity in Vue 3)
- Update main.js to use createApp() instead of Vue.extend()
- Add @vitejs/plugin-vue and configure Vite for Vue 3
- All builds passing, ready for admin UX improvements

third_party/astrolabe/package.json

@@ -23,8 +23,8 @@
     "@nextcloud/router": "^3.0.1",
     "@nextcloud/vue": "^9.0.0",
     "markdown-it": "^14.1.0",
-    "plotly.js-dist-min": "^2.35.3",
     "pdfjs-dist": "^4.0.379",
+    "plotly.js-dist-min": "^2.35.3",
     "vue": "^3.0.0",
     "vue-material-design-icons": "^5.3.1"
   },
@@ -33,6 +33,7 @@
     "@nextcloud/eslint-config": "8.4.2",
     "@nextcloud/stylelint-config": "3.1.1",
     "@nextcloud/vite-config": "1.7.2",
+    "@vitejs/plugin-vue": "^6.0.3",
     "terser": "5.44.1",
     "vite": "7.2.7"
   }