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/upload/UploadSidebar.jsx

@@ -1,5 +1,6 @@
 import React from 'react'
 import TagInput from '../tags/TagInput'
+import Checkbox from '../../Components/ui/Checkbox'
 
 export default function UploadSidebar({
   title = 'Artwork details',
@@ -75,20 +76,17 @@ export default function UploadSidebar({
         </section>
 
         <section className="rounded-xl border border-white/10 bg-white/[0.03] p-4">
-          <label className="flex items-start gap-3 text-sm text-white/90">
-            <input
-              id="upload-sidebar-rights"
-              type="checkbox"
-              checked={Boolean(metadata.rightsAccepted)}
-              onChange={(event) => onToggleRights?.(event.target.checked)}
-              className="mt-0.5 h-5 w-5 rounded-md border border-white/30 bg-slate-900/70 text-emerald-400 accent-emerald-500 focus:ring-2 focus:ring-emerald-400/40"
-            />
-            <span>
-              I confirm I own the rights to this content. <span className="text-red-300">*</span>
-              <span className="mt-1 block text-xs text-white/60">Required before publishing.</span>
-              {errors.rights && <span className="mt-1 block text-xs text-red-200">{errors.rights}</span>}
-            </span>
-          </label>
+          <Checkbox
+            id="upload-sidebar-rights"
+            checked={Boolean(metadata.rightsAccepted)}
+            onChange={(event) => onToggleRights?.(event.target.checked)}
+            variant="emerald"
+            size={20}
+            label="I confirm I own the rights to this content."
+            hint="Required before publishing."
+            error={errors.rights}
+            required
+          />
         </section>
       </div>
     </aside>