- Root cause: Zod schemas for createItem and createCandidate did not
include imageFilename field, so @hono/zod-validator silently stripped
it from validated payloads before reaching the service layer
- Images uploaded successfully but filename was never persisted to DB
- Added imageFilename as optional string to both createItemSchema and
createCandidateSchema
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>