Adds a lane: secret|login field to RouteEntry. The login lane is an
interactive auth bootstrap: it skips the caller-auth precheck (no token
yet — that's the point) and the secret-read gate (it establishes the
identity the gate needs), runs the owner's login command interactively
as the caller via inherited stdio, and rejects --exec. The token stays
in the caller's own store; warden never captures it (G2 holds). Audited
as action: login. key-cape-oidc-login populated as the reference login
entry. Advisory proxy hint updated now that T3 has shipped.
172 passed, lint clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>