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)

app/Http/Controllers/Studio/StudioController.php

@@ -97,6 +97,9 @@ final class StudioController extends Controller
                 'sub_category_id'    => $primaryCategory?->parent_id ? $primaryCategory->id : null,
                 'categories'      => $artwork->categories->map(fn ($c) => ['id' => $c->id, 'name' => $c->name, 'slug' => $c->slug])->values()->all(),
                 'tags'            => $artwork->tags->map(fn ($t) => ['id' => $t->id, 'name' => $t->name, 'slug' => $t->slug])->values()->all(),
+                // Versioning
+                'version_count'       => (int) ($artwork->version_count ?? 1),
+                'requires_reapproval' => (bool) $artwork->requires_reapproval,
             ],
             'contentTypes' => $this->getCategories(),
         ]);