Disambiguates all overloaded terms in the codebase: Person vs AppUser, Chronik (internal) vs Aktivität (user-facing), TranscriptionBlock polygon vs bounding box, DocumentVersion append-only convention, OcrJob lifecycle, SenderModel as persistent entity, Audit log DB-layer caveat, and more. Includes Pending Terms section for audit follow-ups (#388–#392). Refs #397 Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>