Lifts the deep-merge algorithm from apps/speakers/bootstrap.py:merge_names into think/entities/merge.py as a slug-keyed primitive merge_entity(...), exposed via sol call entities merge SOURCE_SLUG TARGET_SLUG. Default-safe (--no-commit); --commit required to mutate. Reduces sol call speakers merge-names to a name-resolving shim that preserves its existing contract including the any-principal rejection. Policy deltas vs. the original merge_names: - source-principal + target-not: transfers principal to target - both-principal: error, no mutation - --no-keep-source-as-aka: skips adding source display name to target.aka while still merging source's own aka list - rejects the merge if any other entity's aka list references the source slug or display name, listing every offending entity id Lifts _dedupe_akas / _dedupe_emails / _dedupe_observations from think/merge.py:_merge_entities into think/entities/merge.py so merge_journals and merge_entity share one implementation. Extracts voiceprint I/O (load_existing_voiceprint_keys, save_voiceprints_batch, save_voiceprints_safely, normalize_embedding, load_entity_voiceprints_file) into think/entities/voiceprints.py so the entity merge primitive does not reach up into apps/speakers. Audit-log line appended to journal/logs/entity-merges.jsonl on successful commit only; dry-run prints a plan JSON with would_* counts and zero disk mutation. Updates the L2 write-owner table in docs/coding-standards.md.