Create migration for events, event_revisions, event_tombstones,
idempotency_nonces, and event_animals tables with ULID checks
and JSON validation. Add Pydantic models with field validators.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Implements Step 1.4: Creates migration for species, locations, products,
feed_types, and users tables with full CHECK constraints. Adds Pydantic
models with validation for all reference types including enums for
ProductUnit and UserRole.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
