Expose bounded relation traversal to agents with regression coverage #91

Work

Add self-describing relation read/write tools or extend existing contracts coherently. Use canonical references, explicit relation kinds, bounded depth/result counts and permission checks for every endpoint. Add examples showing relevant evidence for a selected task.

Acceptance

• Agent can find decisions behind a task and affected work after a decision changes.
• Pagination/truncation is explicit and stable; cycles cannot cause unbounded traversal.
• Scope changes and pending revisions do not leak graph metadata.
• Relation edits do not implicitly complete, archive or approve items.

Dependencies

#82 and persisted relations under #75. Coordinate names/contracts with #76.