Define local-first agentic graph foundation

[mdheller]

Summary

Adds the SourceOS/SociOS local-first agentic graph foundation as an additive architecture and contract layer.

This PR establishes the control-plane spec for integrating SourceOS, Prophet Workspace, Memory Mesh, Agent Registry, Policy Fabric, TurtleTerm, BearBrowser, Mesh Rush, Sherlock, and related runtime repos around one governed graph substrate.

Added

• docs/architecture/local-first-agentic-graph.md
  • Defines SourceIdentity, SourceGraph, SourceStore, SourceSync, SourcePolicy, SourceChannel, and SourceAudit.
• docs/security/agentic-sync-threat-model.md
  • Threat model for remote graph poisoning, memory injection, shell profile injection, policy downgrade, browser-to-local bridge abuse, relay compromise, secret leakage, and agent capability escalation.
• docs/specs/sync-engine-registry.md
  • Canonical sync engines, merge strategies, policy classes, encryption scopes, state machine, and reason codes.
• docs/specs/sourcechannel.md
  • Privileged bridge contract for workspace UI, terminal, browser, MCP, agent runtime, daemon, and admin-console surfaces.
• docs/integration/repo-map.md
  • Estate integration map and M1 manifest acceptance criteria.
• README links to the new agentic graph foundation docs.

Design intent

This keeps sourceos-spec as the constitutional contract repo and prevents downstream implementation repos from inventing separate models for sync, policy, memory, agents, shell, browser, relay, and audit.

Notes

The branch is additive documentation/spec work. It does not rewrite existing schemas or APIs yet.

Follow-up work

• Add JSON Schemas for SourceOSRepoManifest, SyncEngineManifest, SourceChannelEnvelope, SourceGraphWrite, AgentCapabilityLease, PolicyDecision, and AuditEvent.
• Add .sourceos/manifest.json across M1 repos.
• Implement estate scanning and contract validation in sourceos-devtools.