On-chain Registry for Policy Packs and Compliance Verification

Extend the Substrate-based arkavo-node to act as the source of truth for Space governance and cryptographic verification.

### Requirements:

Policy Registry: Store CIDs of versioned Policy Packs.
Reputation Pallet: Implement a "Reputation Vector" that tracks signals (e.g., account age, hardware attestation status, dispute outcomes).
Compliance Logic: A runtime module to verify that submitted Content Objects contain valid signatures from "Attested Edge Agents."
Slashing Mechanism: Logic to degrade the reputation of Edge Agents that are consistently flagged for signing policy-violating content.

Start by mapping the arkavo-node Substrate runtime and the existing pallet or module boundaries for policy storage, reputation, compliance verification, and slashing. Define how versioned Policy Pack CIDs, Reputation Vectors, attested signatures, and policy-violation outcomes connect, then verify that the registry, verification, and reputation behavior satisfy the stated requirements.

Written by the indexing model from the issue text.