feat: upload wizard refactor + vision AI tags + artwork versioning

Upload wizard:
- Refactored UploadWizard into modular steps (Step1FileUpload, Step2Details, Step3Publish)
- Extracted reusable hooks: useUploadMachine, useFileValidation, useVisionTags
- Extracted reusable components: CategorySelector, ContentTypeSelector
- Added TagPicker component (studio-style list picker with AI badge + new-tag insertion)
- Fixed TagInput auto-open bug (hasFocusedRef guard)
- Replaced TagInput with TagPicker in UploadSidebar

Vision AI tag suggestions:
- Add UploadVisionSuggestController: sync POST /api/uploads/{id}/vision-suggest
- Calls vision.klevze.net/analyze/all on upload completion (before step 2 opens)
- Two-phase useVisionTags: immediate gateway call + background DB polling
- Trigger fires on uploadReady (not step change) so tags arrive before user sees step 2
- Added vision.gateway config block with VISION_GATEWAY_URL env

Artwork versioning system:
- ArtworkVersion / ArtworkVersionEvent models
- ArtworkVersioningService: createNewVersion, restoreVersion, rate limiting, ranking decay
- Migrations: artwork_versions, artwork_version_events, versioning columns on artworks
- Studio API routes: GET versions, POST restore/{version_id}
- Feature tests: ArtworkVersioningTest (13 cases)

resources/js/components/upload/UploadStepper.jsx

@@ -4,7 +4,7 @@ export default function UploadStepper({ steps = [], activeStep = 1, highestUnloc
   const safeActive = Math.max(1, Math.min(steps.length || 1, activeStep))
 
   return (
-    <nav aria-label="Upload steps" className="rounded-xl border border-white/50 bg-slate-900/70 px-3 py-3 sm:px-4">
+    <nav aria-label="Upload steps" className="rounded-xl ring-1 ring-white/10 bg-slate-900/70 px-3 py-3 sm:px-4">
       <ol className="flex flex-nowrap items-center gap-3 overflow-x-auto sm:gap-4">
         {steps.map((step, index) => {
           const number = index + 1
@@ -19,7 +19,7 @@ export default function UploadStepper({ steps = [], activeStep = 1, highestUnloc
             : isComplete
               ? 'border-emerald-300/30 bg-emerald-500/15 text-emerald-100 hover:bg-emerald-500/25'
               : isLocked
-                ? 'cursor-default border-white/50 bg-white/5 text-white/40'
+                ? 'cursor-default border-white/10 bg-white/5 text-white/40'
                 : 'border-white/10 bg-white/5 text-white/80 hover:bg-white/10'
 
           const circleClass = isComplete