Update CheckpointID/trailer doc comments to mention ULIDs
Commit
Soph2mo ago
Doc-only follow-up to the ULID understanding layer: the CheckpointID type comment and the CheckpointTrailerKey comment still described the ID as "12 hex characters." Note both supported formats (legacy 12-hex and 26-char ULID) and point at the canonical id.CheckpointPattern / Kind.
Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com Entire-Checkpoint: da0a3dbefa5e