Allow for manual legacy enclave PCR values.

[vreff]

This PR:

• enables manual legacy enclave PCR values in lieu of a gitref to checkout to.
• updates our ECR push job to run on a regular runner.
• Prints measurements more descriptively on attestation errors.
• Publishes our insecure measurements to the job summaries (marks them for testing only).

[github-actions]

AI dashboard check

@vreff the AI Stupid Level dashboard is not currently showing any tracked models at score 55 or lower in the last 24 hours.

Tracked models currently not flagged

• GPT-5.4: gpt-5.4 (score 63, status warning, trend down)
• Claude Opus 4.5: claude-opus-4-5-20251101 (score 72, status good, trend up)
• Claude Opus 4.6: claude-opus-4-6 (score 67, status good, trend stable)
• Claude Opus 4.7: claude-opus-4-7 (score 68, status good, trend up)
• Claude Sonnet 4.5: claude-sonnet-4-5-20250929 (score 64, status warning, trend stable)
• Claude Sonnet 4.6: claude-sonnet-4-6 (score 60, status warning, trend down)

To rerun this check on demand, comment /rerun-ai-dashboard-warning on this PR.

Snapshot: 2026-07-17T18:00:01.970Z from https://aistupidlevel.info (24h view).

[github-actions]

👋 vreff, thanks for creating this pull request!

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