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

resources/scripts/components/base/base-editor/BaseEditor.vue

@@ -15,7 +15,7 @@
         <BaseDropdown width-class="w-48">
           <template #activator>
             <div
-              class="flex items-center justify-center w-6 h-6 ml-2 text-sm text-black bg-white rounded-sm md:h-9 md:w-9"
+              class="flex items-center justify-center w-6 h-6 ml-2 text-sm text-black bg-white rounded-xs md:h-9 md:w-9"
             >
               <EllipsisVerticalIcon class="w-6 h-6 text-gray-600" />
             </div>
@@ -175,7 +175,9 @@ export default {
 }
 </script>
 
-<style lang="scss">
+<style>
+@reference "../../../../css/invoiceshelf.css";
+
 .ProseMirror {
   min-height: 200px;
   padding: 8px 12px;
@@ -209,7 +211,7 @@ export default {
 
   blockquote {
     padding-left: 1rem;
-    border-left: 2px solid rgba(#0d0d0d, 0.1);
+    border-left: 2px solid rgba(13, 13, 13, 0.1);
   }
 
   code {
@@ -236,7 +238,7 @@ export default {
   }
 
   a {
-    color: rgb(var(--color-primary-500));
+    color: var(--color-primary-500);
     text-decoration: underline;
   }
 }