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/admin/components/modal-components/CategoryModal.vue

@@ -53,7 +53,7 @@
           flex
           justify-end
           p-4
-          border-t border-gray-200 border-solid border-modal-bg
+          border-t border-gray-200 border-solid
         "
       >
         <BaseButton

resources/scripts/admin/components/modal-components/CompanyModal.vue

@@ -98,7 +98,7 @@
         </BaseInputGrid>
       </div>
 
-      <div class="z-0 flex justify-end p-4 bg-gray-50 border-modal-bg">
+      <div class="z-0 flex justify-end p-4 bg-gray-50 border-t border-gray-200">
         <BaseButton
           class="mr-3 text-sm"
           variant="primary-outline"

resources/scripts/admin/components/modal-components/DeleteCompanyModal.vue

@@ -38,7 +38,7 @@
         </BaseInputGroup>
       </div>
 
-      <div class="z-0 flex justify-end p-4 bg-gray-50 border-modal-bg">
+      <div class="z-0 flex justify-end p-4 bg-gray-50 border-t border-gray-200">
         <BaseButton
           class="mr-3 text-sm"
           variant="primary-outline"

resources/scripts/admin/components/modal-components/FileDiskModal.vue

@@ -21,7 +21,7 @@
       >
         <template #default="slotProps">
           <div
-            class="z-0 flex justify-end p-4 border-t border-solid border-gray-light"
+            class="z-0 flex justify-end p-4 border-t border-solid border-gray-200"
           >
             <BaseButton
               class="mr-3 text-sm"

resources/scripts/admin/components/modal-components/ItemUnitModal.vue

@@ -37,7 +37,7 @@
           flex
           justify-end
           p-4
-          border-t border-gray-200 border-solid border-modal-bg
+          border-t border-gray-200 border-solid
         "
       >
         <BaseButton

resources/scripts/admin/components/modal-components/NoteModal.vue

@@ -75,7 +75,7 @@ _          />
           justify-end
           px-4
           py-4
-          border-t border-solid border-gray-light
+          border-t border-solid border-gray-200
         "
       >
         <BaseButton
@@ -280,7 +280,7 @@ function closeNoteModal() {
 }
 </script>
 
-<style lang="scss">
+<style>
 .note-modal {
   .header-editior .editor-menu-bar {
     margin-left: 0.5px;

resources/scripts/admin/components/modal-components/RolesModal.vue

@@ -122,7 +122,7 @@
           flex
           justify-end
           p-4
-          border-t border-solid border--200 border-modal-bg
+          border-t border-solid border-gray-200
         "
       >
         <BaseButton

resources/scripts/admin/components/modal-components/TaxTypeModal.vue

@@ -106,7 +106,7 @@
           flex
           justify-end
           p-4
-          border-t border-solid border--200 border-modal-bg
+          border-t border-solid border-gray-200
         "
       >
         <BaseButton

resources/scripts/admin/components/modal-components/custom-fields/CustomFieldModal.vue

@@ -179,7 +179,7 @@
           flex
           justify-end
           p-4
-          border-t border-solid border-gray-light border-modal-bg
+          border-t border-solid border-gray-200
         "
       >
         <BaseButton