760e995ae3
- StorageProvider interface with LocalProvider (S3 placeholder) - File table with entity_type/entity_id references, content type, path - POST /v1/files (multipart upload), GET /v1/files (list by entity), GET /v1/files/:id (metadata), GET /v1/files/serve/* (content), DELETE /v1/files/:id - member_identifier drops base64 columns, uses file_id FKs - File validation: type whitelist, size limits, per-entity max - Fastify storage plugin injects provider into app - 6 API tests for upload, list, get, delete, validation - Test runner kills stale port before starting backend