tasks: add drift sync tasks to align source with architecture specs

tasks/drift/remove-schema-builder.md

@@ -0,0 +1,36 @@
+---
+id: drift/remove-schema-builder
+name: Remove schemaBuilder.ts — replaced by Type.Module() per ADR-009
+status: pending
+depends_on: []
+scope: single
+risk: trivial
+impact: component
+level: implementation
+---
+
+## Description
+
+The `SchemaBuilder` class in `src/graphs/schemaBuilder.ts` is the old fluent builder pattern for constructing graph type definitions. ADR-009 and the metagraph-module.md spec explicitly replace it with `Type.Module()` construction. The `SchemaBuilder` is unreleased API — it has no consumers outside this package.
+
+Remove the file and its re-export from `src/graphs/mod.ts`.
+
+## Acceptance Criteria
+
+- [ ] `src/graphs/schemaBuilder.ts` is deleted
+- [ ] `src/graphs/mod.ts` no longer exports from `schemaBuilder.ts`
+- [ ] No remaining imports of `SchemaBuilder` anywhere in `src/` or `test/`
+- [ ] `deno check mod.ts` passes
+
+## References
+
+- docs/architecture/metagraph-module.md — "SchemaBuilder removed; replaced by Type.Module() construction"
+- docs/architecture/decisions/009-typebox-module-replaces-schemabuilder.md
+
+## Notes
+
+> To be filled by implementation agent
+
+## Summary
+
+> To be filled on completion