chore(missing_docs): refresh surface map and snapshot after drift-watch audit

Bookkeeping for the missing_docs drift-watch run: repoint the surface map at the
renamed /agents/ doc paths, add mappings for the newly GA flags, mark the new
Warp Agent CLI-only surfaces internal, and regenerate the surface snapshot.

Co-Authored-By: Oz <oz-agent@warp.dev>

Author: hongyi-chen