vf-derive

Derive a profile in another language.

Read ../voice-forge/SKILL.md (the voice-forge skill next to this one) and follow it. If that path does not resolve, use the installed voice-forge skill by name.
Then read ../voice-forge/references/derive.md and follow it.
Two names after the command: the source profile and the new one (/vf-derive explainer-es explainer-en). One name plus update: bring in later changes from the source (/vf-derive explainer-en update).
Tell the user clearly that the new profile is provisional: a starting point that still needs training.