GovOPlaN Policy

govoplan-policy owns policy and retention API route contributions during the GovOPlaN module split.

The current package delegates to the legacy access administration implementation while route ownership is separated before model migration.

Policy decision and provenance payloads use the shared kernel DTOs documented in docs/POLICY_DECISION_PROVENANCE.md and /mnt/DATA/git/govoplan-core/docs/POLICY_CONTRACTS.md.

Hierarchical policy evaluation, delegation ceilings, and write simulations are implemented in govoplan_policy.backend.hierarchy. Privacy retention uses that shared helper and exposes /api/v1/admin/privacy-retention/policies/{scope}/simulate for preflight checks before saving lower-level policy changes.