fix(CI): TPM test_certify fails due to stale NV index

[prodnull]

Problem

test_certify_returns_attestation_evidence panics with:

NV Index or persistent object already defined

4/5 TPM tests pass. This test fails because earlier tests create a persistent TPM object and don't clean up.

Root Cause

Test isolation — swtpm state shared across all --ignored tpm tests. Persistent handle 0x81000001 created by earlier test, not evicted.

Fix

Each test should evict the persistent handle in setup, or use unique handles per test.

File: prmana-agent/src/crypto/tpm_signer.rs:845
Pre-existing — not caused by OSS/enterprise refactor.