Module store 

Graph storage backends for AINL memory.

Defines the GraphStore trait and the SQLite implementation.

Referential integrity (SQLite)

ainl_graph_edges uses real FOREIGN KEY (from_id) / FOREIGN KEY (to_id) references to ainl_graph_nodes(id) with ON DELETE CASCADE. SqliteGraphStore::open and SqliteGraphStore::from_connection run PRAGMA foreign_keys = ON on the handle.

Databases created before these constraints used a plain edges table; SqliteGraphStore::ensure_schema runs a one-time migrate_edges_add_foreign_keys rebuild. Edge rows whose endpoints are missing from ainl_graph_nodes cannot be kept under FK rules and are omitted from the migrated copy.

Above the database (still recommended)

• Eager checks: SqliteGraphStore::write_node_with_edges, SqliteGraphStore::insert_graph_edge_checked give clear errors without relying on SQLite error text alone.
• Repair / forensic import: SqliteGraphStore::import_graph with allow_dangling_edges: true is the supported way to load snapshots that violate referential integrity: FK enforcement is disabled only for the duration of that import, then turned back on. Follow with SqliteGraphStore::validate_graph before resuming normal writes on the same connection.
• Semantic graph checks: SqliteGraphStore::validate_graph (agent-scoped edges, dangling diagnostics, cross-agent boundary counts, etc.) — orthogonal to FK row existence.

SQLite tables integrate with existing openfang-memory schema where applicable.

Structs

SqliteGraphStore

SQLite implementation of GraphStore

Traits

GraphStore

Graph memory storage trait - swappable backends