[3.x] Upgrade Vite 7 to Vite 8

HYDEPHP_V3_PLANNING.md

@@ -20,6 +20,7 @@ Having this document in code lets us know the devlopment state at any given poin
 
 - Removed the legacy `checkForDeprecatedRunMixCommandUsage` check and the placeholder `--run-dev`/`--run-prod` options from the `build` command, which were kept in v2 only to surface a helpful error message. ([#2461](https://github.com/hydephp/develop/pull/2461))
 - Removed the deprecated `hyde.server.dashboard` boolean config check from `DashboardController::enabled()`, which was kept in v2 for backwards compatibility but had since then been replaced with `hyde.server.dashboard.enabled`. ([#2461](https://github.com/hydephp/develop/pull/2462))
+- Upgraded the bundled `vite` dependency from v7 to v8, and widened the `hyde-vite-plugin`'s `vite` peer dependency range from `>=6.3.5 <8.0.0` to `>=6.3.5 <9.0.0` so downstream projects can adopt Vite 8 without waiting for a new plugin major. The plugin's build config now targets Vite 8's Rolldown-based bundler (`rolldownOptions` instead of `rollupOptions`). ([#2414](https://github.com/hydephp/develop/pull/2414))
 
 ### Breaking Changes
 

UPGRADE.md

@@ -38,7 +38,19 @@ git commit -m "Pre-upgrade backup before HydePHP v3.0"
 
 ### Update Node Dependencies
 
-//
+HydePHP v3 upgrades the bundled `vite` dependency from v7 to v8. Update your `package.json` `devDependencies` to require the new major version:
+
+```json
+{
+    "devDependencies": {
+        "vite": "^8.0.0"
+    }
+}
+```
+
+Then run `npm install` (or your package manager's equivalent) to pick up the update.
+
+If you have a custom `vite.config.js` that overrides `build.rollupOptions`, note that Vite 8 builds with Rolldown by default. The `hyde-vite-plugin` now configures its own build options under `build.rolldownOptions` rather than `build.rollupOptions` — if your custom config only sets `rollupOptions`, double check your output still ends up where you expect after upgrading.
 
 ## Step 2: Replace the Removed `rebuild` Command