WallGuard runtime wall-context lookup and subject authority state

[mdheller]

Parent: SocioProphet/sociosphere#443
Depends on: #45
Depends on: SocioProphet/policy-fabric#93

Purpose

Implement the Agent Registry runtime surface for WallGuard active wall context lookup.

Policy Fabric owns final WallGuard decisions. Agent Registry owns authoritative subject/session context required by that decision layer: wall memberships, acknowledgments, recusal/revocation state, session scope, and allowed memory/tool classes.

Runtime objective

Provide a deterministic runtime lookup path that can answer:

• which wall(s) an agent or human subject is currently authorized for
• whether membership is active, revoked, expired, or missing
• whether the subject is recused
• whether the session is clean, wall-scoped, contaminated, or unknown
• which memory compartments and tool classes are allowed to be considered by downstream evaluators

Required behavior

• Resolve agentRef / subjectRef to an active WallGuard context record.
• Return fail-closed context for missing, revoked, expired, recused, contaminated, or unknown session state.
• Preserve the landed AgentWallContext contract as the external shape or compatibility layer.
• Produce receipt/evidence refs suitable for Policy Fabric and Core Ledger.
• Do not perform final policy authorization locally; provide context to Policy Fabric.

Suggested files

• tools/wallguard_context_lookup.py
• contracts/wallguard/runtime/*.json
• tools/validate_wallguard_context_lookup.py
• Makefile target validate-wallguard-context-lookup

Acceptance criteria

• Same-wall active agent context resolves as usable for Policy Fabric evaluation.
• Revoked membership resolves fail-closed.
• Recused subject resolves fail-closed.
• Contaminated/unknown session does not expose global or firm-approved memory compartments.
• Missing context returns an explicit missing-context state, not an implicit allow.
• Runtime output is sufficient for Policy Fabric evaluator and downstream AgentPlane/Memory Mesh/Sherlock surfaces.
• No dependency on cascade, presidio, OrchestraOS, or noncanonical/unlicensed code.

Non-goals

• Do not implement Policy Fabric decisions in Agent Registry.
• Do not implement AgentPlane collaboration checks here.
• Do not implement Memory Mesh read/write behavior here.