Add src/graphs/modules/metagraph.ts exporting Metagraph as Type.Module()
with Config (Union defaults for type, Boolean defaults for multi/allowSelfLoops),
BaseNode (optional created/modified/metadata with Type.Unknown()), and
BaseEdge (type string, optional metadata with Type.Unknown()). Also export
GRAPH_STATUS const and GraphStatus TypeBox schema for sqlite host usage.
Update mod.ts to re-export from modules/metagraph.ts.
The verbatim-module-syntax lint rule was correctly flagging that
GraphConfig is only used in a type position (typeof GraphConfig). Since
typeof resolves purely at the type level, import type works fine here
and is the correct form. No lint exclusion needed.
Also: deno fmt across all files (markdown line wrapping).
