The default-relative ladder conflicts with per-session overrides: schemas
are registry-global while the effective mode is switchable, so a session
overridden NARROWER than the default loses exactly the lever it needs — a
workspace-write default with a read-only override could only request
danger-full-access (forced over-escalation), and a danger-full-access
default with a read-only override advertised no fields at all (confined,
no escalation path). The enum now pins the closed target vocabulary
(workspace-write / danger-full-access) whenever the executor confines;
strict widening is enforced per call against the session effective mode
(override ?? default), failing closed without prompting anyone. The
default-relative ladder and per-session dynamic schemas move to
Alternatives; the harmless Risks claim is corrected to name the runtime
check as the safety boundary.