Masahiko AMANO
8dd2d631e5
refactor: strengthen domain layer types and add missing page types
- DomainError struct with Code() string method replaces plain errors.New
sentinels; errors.Is() still works via pointer equality
- UUIDCreatedAt(uuid.UUID) time.Time helper extracts timestamp from UUID v7
- Add TagOffsetPage, CategoryOffsetPage, PoolOffsetPage
- FileListParams fields grouped with comments matching openapi.yaml params
- Fix mismatched comment on UserPage
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>