`[2026-06-16]` **Self-drive auth identity: bound session-create uses the CONSUMER Heimdall key as bearer, NOT `WORLDTREE_API_KEY`.** Worldtree signs the Bifrost handshake JWT with the session-create bearer (canary key → handshake 401; consumer key → 200). Two keys, two identities. Proven by hand; documented in `docs/bifrost-self-test.md`; load-bearing for #17's Bind half.