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/UploadDropzone.jsx

@@ -67,7 +67,7 @@ export default function UploadDropzone({
   }
 
   return (
-    <section className={`rounded-xl border bg-gradient-to-br p-0 shadow-[0_12px_32px_rgba(0,0,0,0.35)] transition-colors ${invalid ? 'border-red-400/45 from-red-500/10 to-slate-900/45' : 'border-white/50 from-slate-900/80 to-slate-900/50'}`}>
+    <section className={`rounded-xl bg-gradient-to-br p-0 shadow-[0_12px_32px_rgba(0,0,0,0.35)] transition-colors ${invalid ? 'ring-1 ring-red-400/40 from-red-500/10 to-slate-900/45' : 'ring-1 ring-white/10 from-slate-900/80 to-slate-900/50'}`}>
       {/* Intended props: file, dragState, accept, onDrop, onBrowse, onReset, disabled */}
       <motion.div
         data-testid="upload-dropzone"
@@ -100,7 +100,7 @@ export default function UploadDropzone({
         }}
         animate={prefersReducedMotion ? undefined : { scale: dragging ? 1.01 : 1 }}
         transition={dragTransition}
-        className={`group rounded-xl border-2 border-dashed border-white/50 py-6 px-4 text-center transition hover:border-accent/60 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-sky-300/70 ${locked ? 'cursor-default bg-white/5 opacity-75' : 'cursor-pointer'} ${invalid ? 'border-red-300/70 bg-red-500/10 shadow-[0_0_0_1px_rgba(248,113,113,0.2)]' : dragging ? 'border-cyan-300 bg-cyan-500/20 shadow-[0_0_0_1px_rgba(103,232,249,0.35)]' : locked ? 'bg-white/5' : 'bg-sky-500/5 hover:bg-sky-500/12'}`}
+        className={`group rounded-xl border-2 border-dashed border-white/15 py-6 px-4 text-center transition hover:border-accent/60 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-sky-300/70 ${locked ? 'cursor-default bg-white/5 opacity-75' : 'cursor-pointer'} ${invalid ? 'border-red-300/70 bg-red-500/10 shadow-[0_0_0_1px_rgba(248,113,113,0.2)]' : dragging ? 'border-cyan-300 bg-cyan-500/20 shadow-[0_0_0_1px_rgba(103,232,249,0.35)]' : locked ? 'bg-white/5' : 'bg-sky-500/5 hover:bg-sky-500/12'}`}
       >
         <h3 className="mt-3 text-sm font-semibold text-white">{title}</h3>
         <p className="mt-1 text-xs text-soft">{description}</p>
@@ -155,7 +155,7 @@ export default function UploadDropzone({
         />
 
         {(previewUrl || (fileMeta && String(fileMeta.type || '').startsWith('image/'))) && (
-          <div className="mt-3 rounded-lg border border-white/50 bg-black/25 px-3 py-2 text-left text-xs text-white/80">
+          <div className="mt-3 rounded-lg ring-1 ring-white/10 bg-black/25 px-3 py-2 text-left text-xs text-white/80">
             <div className="font-medium text-white/85">Selected file</div>
             <div className="mt-1 truncate">{fileName || fileHint}</div>
             {fileMeta && (