Add StorageReceipt schema for local LVM and TopoLVM cache evidence

[mdheller]

Context

Agent Machine treats storage/cache as a first-class scheduling and evidence surface. Local LVM, TopoLVM PVCs, tmpfs, filesystem paths, object stores, and remote volumes need receipt semantics before sensitive activation.

Required outcome

Define a StorageReceipt schema and examples for local LVM and Kubernetes TopoLVM storage/cache/evidence volumes.

Acceptance criteria

• Add contracts/storage-receipt.schema.json.
• Receipt covers backend type, volume class, cache tier, mount path or PVC name, filesystem type, size/free bytes, encryption posture, quota, snapshot lineage, policy domain, sensitivity, wipe/eviction status, timestamp, and probe/runtime version.
• Raw prompts, raw KV-cache contents, private memory, credentials, and provider secrets are forbidden.
• Add examples for local LVM warm cache and TopoLVM evidence PVC.
• StorageReceipt references can be included in AgentPlane runtime evidence payloads.

Related docs

• docs/architecture/world-class-release-gate.md
• docs/architecture/local-lvm-and-topolvm-profile.md
• docs/architecture/receipt-chain.md