Save episode character direction without generating or spending credits.

Existing images and voices remain unchanged. avatarPrompt guides headshots and sheets; figurePrompt guides body shots. signatureItems (what only this person wears or carries) is saved on the project cast canon for every episode. A person on the project cast canon whom the episode does not name (a deck or trailer draws them from the canon) takes signatureItems alone, saved on their canon entry (projectCast: true in the answer); any other field sent for them is refused by name. When the canon cannot tell who the character is, nothing is saved and a 409 names the candidates; the writer answers with sameAs (the character IS that canon person, so the script name becomes their alias) or newPersonName (someone else, saved under that full name). A separate quote and confirmation are required to replace assets.