Upgrade to Vite 8 and Tailwind CSS 4 (#595)

- Vite 6 → 8 (Rolldown bundler), laravel-vite-plugin 1 → 3, @vitejs/plugin-vue 5 → 6
- Tailwind CSS 3 → 4 with CSS-based config (@theme, @plugin, @utility)
- Add @tailwindcss/vite plugin, remove postcss/autoprefixer/sass
- Convert SCSS files to plain CSS (resources/sass → resources/css)
- Migrate tailwind.config.js to CSS @theme directives
- Rename deprecated utility classes (shadow-sm→shadow-xs, outline-none→outline-hidden,
  rounded-sm→rounded-xs, bg-gradient-to→bg-linear-to, ring→ring-3)
- Migrate opacity utilities to color modifiers (bg-opacity, text-opacity,
  border-opacity, ring-opacity → color/N syntax)
- Update primary color CSS vars to full rgb() values for TW4 color-mix()
- Fix border-l color specificity for sidebar navigation (TW4 default border
  color changed from gray-200 to currentColor)
- Fix invalid border color classes (border-grey-light, border-modal-bg, border--200)
- Add @reference directive for @apply in Vue component style blocks
- Convert Vue component <style lang="scss"> blocks to plain CSS

vite.config.js

@@ -2,6 +2,7 @@ import { defineConfig } from 'vite';
 import vue from '@vitejs/plugin-vue';
 import { resolve } from 'path';
 import laravel from 'laravel-vite-plugin';
+import tailwindcss from '@tailwindcss/vite';
 
 export default defineConfig({
   server: {
@@ -12,7 +13,6 @@ export default defineConfig({
   },
   resolve: {
     alias: {
-      "vue-i18n": "vue-i18n/dist/vue-i18n.cjs.js",
       '@': resolve(__dirname, './resources/'),
       $fonts: resolve(__dirname, './resources/static/fonts'),
       $images: resolve(__dirname, './resources/static/img')
@@ -20,26 +20,17 @@ export default defineConfig({
     extensions: ['.js', '.ts', '.jsx', '.tsx', '.json', '.vue', '.mjs']
   },
   plugins: [
+    tailwindcss(),
     vue({
       template: {
         transformAssetUrls: {
-          // The Vue plugin will re-write asset URLs, when referenced
-          // in Single File Components, to point to the Laravel web
-          // server. Setting this to `null` allows the Laravel plugin
-          // to instead re-write asset URLs to point to the Vite
-          // server instead.
           base: null,
-
-          // The Vue plugin will parse absolute URLs and treat them
-          // as absolute paths to files on disk. Setting this to
-          // `false` will leave absolute URLs un-touched so they can
-          // reference assets in the public directory as expected.
           includeAbsolute: false,
         },
       },
     }),
-    laravel([
-      'resources/scripts/main.js'
-    ])
+    laravel({
+      input: ['resources/scripts/main.js'],
+    })
   ]
 });