v0.6.0

What's new

• feat: Defaulter hook — dgdao now calls ApplyDefaults(ctx) on the model before validation in Insert, Upsert, Update, and LoadOrStore (not LoadAndDelete), so a model can populate default field values before a write. Because it runs before validation, a defaulted field can satisfy a validate:"required" rule. Applies per-element across slices for batch writes.

Purely additive — models that don't implement Defaulter are unaffected. See DEFAULTER.md.