Import improvements:
- importSingleFurni now accepts sourceSwfBaseUrl, nitroBaseUrl, iconBaseUrl
params to try source-specific asset downloads before falling back to
the official Habbo CDN (images.habbo.com)
- Source-specific URL cascade:
1. Try sourceSwfBaseUrl/hof_furni/{rev}/{name}.swf
2. Try sourceNitroBaseUrl/{name}.nitro (pre-made nitro bundles)
3. Fallback to images.habbo.com/dcr/hof_furni/{rev}/{name}.swf
- Same fallback chain for icon downloads
- Clone sources can now have empty nitroBaseUrl/iconBaseUrl (retro
hotels without nitro support)
- Added VirtualCity source (verified SWF downloads via virtualc.nl/dcr)
- Added sourceSwfBaseUrl field to CloneSource interface
- Both batch and single import routes pass source params through
- Clone POST route accepts sourceSwfBaseUrl, makes nitro/icon optional
- Nitro fallback download tries .nitro files before SWF conversion