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>