ui-svelte: upgrade to vite 8 (#585)

Upgrade vite and related dependencies to take advantage of Vite 8's
improved build times via Rolldown and Oxc.

- vite: ^6.3.5 → ^8.0.0
- @sveltejs/vite-plugin-svelte: ^5.0.3 → ^7.0.0
- svelte: ^5.19.0 → ^5.46.4
- vite-plugin-compression2: ^2.4.0 → ^2.5.1
- vitest: ^4.0.18 → ^4.1.0

---------

Co-authored-by: Claude <noreply@anthropic.com>

ui-svelte/.npmrc

@@ -0,0 +1 @@
+legacy-peer-deps=true

ui-svelte/package.json

@@ -12,18 +12,18 @@
     "test:watch": "vitest"
   },
   "devDependencies": {
-    "@sveltejs/vite-plugin-svelte": "^5.0.3",
+    "@sveltejs/vite-plugin-svelte": "^7.0.0",
     "@tailwindcss/vite": "^4.1.8",
     "@tsconfig/svelte": "^5.0.4",
     "@types/hast": "^3.0.4",
     "@types/node": "^25.1.0",
-    "svelte": "^5.19.0",
+    "svelte": "^5.46.4",
     "svelte-check": "^4.1.4",
     "tailwindcss": "^4.1.8",
     "typescript": "~5.8.3",
-    "vite": "^6.3.5",
-    "vite-plugin-compression2": "^2.4.0",
-    "vitest": "^4.0.18"
+    "vite": "^8.0.0",
+    "vite-plugin-compression2": "^2.5.1",
+    "vitest": "^4.1.0"
   },
   "dependencies": {
     "highlight.js": "^11.11.1",