Addresses #548 and #545.
#548: processScenarioSchema required a leading "/" for executable,
working_directory and filesystem_roots, so no process scenario could be
expressed on Windows at all. The report suggested node:path's isAbsolute, but
that answers for the host running the check: on Linux `C:\tools` is not
absolute, so a scenario captured on Windows would fail validation when it is
replayed, compared, or asserted in a test on another host. A boundary schema
must not vary with its evaluator, so the check accepts the POSIX form, a
Windows drive path and a UNC share everywhere. The rejection message now names
the constraint instead of leaving the caller to infer it from "invalid request".
The HTTP `path` field inside `checkpoints` is an URL path and is deliberately
left alone.
I checked whether this merely moved the failure downstream: containment is
enforced by isPathWithinRoot, which already uses host-aware path.relative, so
validation really was the only blocker.
#545: when a scope is inside the administrator ceiling but no grant was ever
issued, the denial still pointed at widening the ceiling -- advice that cannot
help, since the ceiling already permits the operation. The `missing` payload is
computed against candidate *grants*, so it describes what a grant must cover,
not a ceiling gap. `PermissionRemediation` gains a `grant` variant saying
exactly that, and PermissionAuthority selects it when the denial is not a
ceiling violation. An explicitly requested remediation is still honoured, and a
genuine ceiling violation still says "configure".
e793e124a2