Release 2.12.2

See https://docs.lamin.ai/changelog/2026#db-2-12-2

What's Changed

• ✨ Enable passing revises_id instead of revises Artifact initialization by @Koncopd in #4035
• ⬆️ Upgrade lamindb-setup by @Koncopd in #4039
• 🐛 Validate defaults for optional non-nullable schema features by @AllaVinner in #4038
• 📝 Document feature nullability and optionality by @AllaVinner in #4034
• 🐛 If through_values is set in a feature, treat to-be-populated timestamp correctly during validation by @falexwolf in #4040
• 📝 Fix stale dtype documentation references by @AllaVinner in #4042
• 🐛 Fix Record.from_dataframe() for nullable features / columns by @AllaVinner in #4041
• ✨ Add tracking for AgentCore transcripts by @ebadukhan in #4036
• 🐛 Amend ordered_set in inferred schemas by @falexwolf in #4043

Full Changelog: 2.12.1...2.12.2