The internal settings schema reference (used by the update-config skill and related tooling) now shows fable as a valid model option: "model": "sonnet", // or "fable", "opus", "haiku", full model ID.
Evidence
Settings schema doc (search for "// or \"fable\", \"opus\", \"haiku\"")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
