Expand description
Bidirectional epoch-ref ↔ human-ref translator.
Mirrors Ruby’s MPS::RefResolver exactly.
Human ref format:
Top-level: {type}-{n} e.g. task-1, note-2, mps-1
Nested: {parent_human}.{idx} e.g. mps-1.1, task-2.3
The resolver is ephemeral — instantiated per-request from a parsed elements map.