- FileValidationPipe now supports maxSizeByMimeType for per-MIME-type size limits
- Images: max 10MB, Video (MP4): max 100MB
- Oversized files return 413 Payload Too Large instead of 400 Bad Request
- MIME type validation runs before size check for clearer error messages
- Multer module limit raised to 100MB (per-type enforcement in pipe)
- Added 413 ApiResponse to Swagger docs on upload endpoint
- Added comprehensive unit tests for FileValidationPipe (16 test cases)
Co-Authored-By: Paperclip <noreply@paperclip.ing>
Add DuplicateDetector domain service that flags potential duplicate listings
using PostGIS ST_DWithin geo-proximity (100m radius) combined with trigram-based
title similarity (>70% threshold). Detection runs during CreateListing but never
blocks creation — warnings are returned in the response for seller/admin review.
Co-Authored-By: Paperclip <noreply@paperclip.ing>