Add full character management system with enriched profiles (bio, traits, arcs, motivation, conflict, secrets), relationship mapping between characters with types and strength, character search/filter by role and arc type, and character statistics (scene count, dialogue, screen time). Includes database schema, tRPC router procedures, SolidJS components, API hooks, and unit tests. Co-Authored-By: Paperclip <noreply@paperclip.ing>