feat: Nova UI component library + Studio dropdown/picker polish

- Add Nova UI library: Button, TextInput, Textarea, FormField, Select,
  NovaSelect, Checkbox, Radio/RadioGroup, Toggle, DatePicker,
  DateRangePicker, Modal + barrel index.js
- Replace all native <select> in Studio with NovaSelect (StudioFilters,
  StudioToolbar, BulkActionsBar) including frosted-glass portal and
  category group headers
- Replace native checkboxes in StudioGridCard, StudioTable, UploadSidebar,
  UploadWizard, Upload/Index with custom Checkbox component
- Add nova-scrollbar CSS utility (thin 4px, semi-transparent)
- Fix portal position drift: use viewport-relative coords (no scrollY offset)
  for NovaSelect, DatePicker and DateRangePicker
- Close portals on external scroll instead of remeasuring
- Improve hover highlight visibility in NovaSelect (bg-white/[0.13])
- Move search icon to right side in NovaSelect dropdown
- Reduce Studio layout top spacing (py-6 -> pt-4 pb-8)
- Add StudioCheckbox and SquareCheckbox backward-compat shims
- Add sync.sh rsync deploy script

resources/js/components/Studio/StudioToolbar.jsx

@@ -1,4 +1,5 @@
 import React from 'react'
+import NovaSelect from '../ui/NovaSelect'
 
 const sortOptions = [
   { value: 'created_at:desc',      label: 'Latest' },
@@ -37,17 +38,14 @@ export default function StudioToolbar({
       </div>
 
       {/* Sort */}
-      <select
-        value={sort}
-        onChange={(e) => onSortChange(e.target.value)}
-        className="px-3 py-2.5 rounded-xl bg-nova-900/60 border border-white/10 text-white text-sm focus:outline-none focus:ring-2 focus:ring-accent/50 appearance-none cursor-pointer min-w-[160px]"
-      >
-        {sortOptions.map((opt) => (
-          <option key={opt.value} value={opt.value} className="bg-nova-900 text-white">
-            {opt.label}
-          </option>
-        ))}
-      </select>
+      <div className="min-w-[160px]">
+        <NovaSelect
+          options={sortOptions}
+          value={sort}
+          onChange={onSortChange}
+          searchable={false}
+        />
+      </div>
 
       {/* Filter toggle */}
       <button