Save the project cast canon.

Set once per project; new episodes seed each matching character's canonical portrait, body, and character-sheet assets before generation so they are not re-rendered. Project-wide character design and visual language live in the Series Bible. Each character also carries aliases (the script cue names that are this person) and signatureItems (what only this person wears or carries; videos with two or more people need them for each person). characters merges by name or alias; pass arrayMode: "replace" to send the complete roster. Unknown keys are refused. The answer carries the same identity warnings as the read. An explicit cast restyle remains an episode override.