PF-VA: pin ovk-basic-v0 verifier profile for pf-core-v0.7.0

[fraware]

Companion ticket: pin verifier profile for pf-core-v0.7.0

Source: PF-Core pf-core-v0.7.0 (commit 0330172b09399029fb6bd0f70c5b411039dd9c36)
Spec: https://github.com/SentinelOps-CI/provability-fabric-core/blob/pf-core-v0.7.0/docs/pf-core/pf-va-pr-artifacts/ovk-profile-pin-pr-spec.md
Pin: https://github.com/SentinelOps-CI/provability-fabric-core/blob/pf-core-v0.7.0/adapters/pcs/fixtures/ovk-verifier-profile/verifier_profile.json

Goal

OVK documents / CI pins the ovk-basic-v0 verifier profile config digest so reward-binding VerifierConfigurationPinned can reference an immutable profile. Checker invocation remains future work; this PR only pins the profile artifact.

Acceptance

Load the pinned profile JSON (from PF-Core vendored fixture or the mirrored path in this repo) and confirm it parses as JSON with:

• profile_id: ovk-basic-v0
• config_digest: cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
• schema_version: pcs.verifier_profile.v0

Non-claims

Profile pin does not prove verifier accuracy or false-acceptance metrics.