chore: relocate elevenlabs-agents/governance.yaml out of the public tree

[wranngle]

What & how to reproduce

elevenlabs-agents/governance.yaml is a live voice-agent operations inventory (deployment identifiers, phone routing, client-facing agent names), not knowledge-base content. It has been tracked since the initial commit and the directory is one of nkb's own SEARCH_ROOTS (scripts/nkb.mjs:10), so nkb search surfaces its contents as hits in a public repo.

Follow-up:

1. Move the file to the private profile/config store.
2. Purge it from this repo (and history if warranted).
3. Drop elevenlabs-agents from SEARCH_ROOTS and rebuild dist/index.json.

Area

core