Admit SEH in standalone driver-host, HAL, and PnP harnesses

[stakach]

Goal

Bring the older isolated driver-host, HAL, and PnP native integration harnesses under an explicit SEH admission model. Issue #11 proves the hosted executive driver-domain path; these standalone harnesses still contain direct PE DriverEntry, dispatch, ISR/DPC, and callback invocations and must not be treated as covered by that proof.

Acceptance

• Inventory direct PE call sites in components/hal-svc, components/pnp-svc, and components/driver-host-* and identify each harness image/stack/fault ownership model.
• Admit PE unwind metadata and exact foreign-call boundaries per harness, or retire a harness that has been replaced by the executive path.
• Retain physical fault/callback ownership across nested calls and deliver provider exceptions without synthetic results or replay.
• Add focused crate checks and bounded native fixture proof for each surviving harness family.
• Review and merge with a clean tree.

Depends on #11 for the executive-host reference implementation.