Add terraform policy to the policy registry

[kuangwojia-netizen]

Fixes #117

Adds signetry_core/policies/terraform.yaml for a Terraform module tree.

• Author: kuangwojia-netizen
• allowed_paths includes modules/** and environments/** so environments/prod/** is an exception inside an allowed tree
• caution: notes that validate/fmt do not mean apply-safe
• Starter YAML adapted (not pasted as-is)

Acceptance intended: pytest tests/test_policy_registry.py green.

[kuangwojia-netizen]

@bkd-dotcom First-time contributor workflows are waiting on approval (CI / CodeQL / Reviewer show action_required). Could you approve the workflows on this PR so pytest tests/test_policy_registry.py can run? Thank you.

[github-actions]

Signetry Reviewer — 🟡 Needs human review

A human should decide — the required check is pending.

Deterministic gates (the authority)

Gate	Status
Required status check	⏳ pending
Secret scan	✅ clean
CI permission / OIDC	✅ no forbidden change
Dependency skew	✅ ok
All green	❌

Findings

No issues found by the deterministic scanners.

Merge

A human should review and merge.

This review is advisory. It never merges on its own judgement — the deterministic gates + a human are the authority. Findings can have false negatives; a green bot verdict is not a guarantee.