Re-vendor the AuthZEN surface artifact at the spec pin and record its commit

[saurabhjain1592]

Problem

tests/fixtures/authzen-surface.json is the artifact scripts/gen_authzen_types.py generates this SDK's AuthZEN types from. It is byte-identical to the platform's AuthZEN surface artifact at platform commit 80953b7ad.

The wire-shape snapshot this SDK pins is at platform commit 36e0e96b7e5c16626d394272b727b533f2b94a04. The platform's artifact there differs from the vendored copy in exactly one member, source_schema_sha256. The enums and types are identical, the 14 obligation types included, so the generated types would not change.

Nothing ties the vendored artifact to a platform commit. This drift was found only by comparing bytes, and the next change to the surface would be missed the same way.

Measured at this repository's main (90175edf4).

Proposed change

• Re-vendor the artifact from the platform at the pinned commit.
• Record the commit the artifact was taken from beside it, and check in CI that it equals the commit the wire-shape snapshot pins, the way the snapshot headers are checked.
• Regenerate the types and confirm the diff is source_schema_sha256 alone.

Target

The SDK release that follows platform v11.1.0. This is not part of the v11.0.0 typed-policy or PEP handshake work.

This repository has no milestones, so the v11.1.0 label marks the target.