chore: pin vite@^8 line to 8.1.0

Bump the Vite 8 resolution (unplugin direct dep + vitest@4 transform
pipeline) from 8.0.10 to latest stable 8.1.0 via scoped pnpm override.
Leaves the vite 5/6/7 lines (consumers, VR harness) untouched.

Verified: unplugin build clean; vitest green on @rozie/unplugin
(150 tests) and @rozie/core (1693 tests).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KSYH6VBAJwa7nYy4AksuNH

Author: serpentblade

package.json

@@ -40,6 +40,9 @@
     "@rozie-ui/headless-core": "workspace:*"
   },
   "pnpm": {
+    "overrides": {
+      "vite@^8": "8.1.0"
+    },
     "packageExtensions": {
       "@analogjs/vite-plugin-angular": {
         "peerDependencies": {