Graph-store evolution — SQLite to networked SQL (post-MVP, D5)

Context

Post-MVP residual workstream under Epic #11730. The Agent OS graph store (Memory Core + relations) runs on SQLite. Epic #11720's MVP cloud deployment keeps SQLite on a mounted volume — adequate for a single-instance tenant deployment. Discussion #11718 flagged D5: evolving the graph store to a networked SQL backend for multi-instance / higher-scale deployments.

Gating Condition

Pursued when a deployment needs multi-instance graph access or scale beyond what single-instance SQLite + mounted volume supports. Not triggered for the single-tenant MVP. Until then: captured intent, not active work.

Scope

• Evaluate networked SQL backends for the graph store; define the migration path from SQLite.
• Concurrency / multi-writer semantics; behaviour of the cross-daemon lease model (ADR 0009) under a networked backend.
• Backward-compatible migration tooling.

Acceptance Criteria

• A post-MVP decision record (ADR-class, distinct from the #11720 MVP ADR set) selects the backend + migration path — OR records "SQLite + mounted volume remains sufficient" with the falsifying evidence.
• If adopted: migration tooling + the lease model verified under the networked backend.

Out of Scope

• The MVP SQLite + mounted-volume baseline — owned by #11720 (Sub C #11724).
• The #11720 MVP deployment ADR set — that is #11720 owner-map scope.

Related

• Parent: #11730 (Post-MVP Residual Workstreams)
• Origin Discussion: #11718 (D5)
• ADRs: 0009 (cross-daemon lease — directly affected by a networked backend)

Origin Session ID

8e1dc8ca-b5a5-4479-b3cf-31918eb4a5b2