chore: absorbe nakui (ERP matemático) en modules/nakui

- crates/modules/nakui/core/: el crate nakui-core (4 bins, tests).
  Deps directas (serde, rhai, surrealdb, petgraph, sha2, uuid, tokio,
  thiserror v1) — no convertidas a workspace = true en esta pasada.
- crates/modules/nakui/modules/{inventory,sales,treasury}/: datos
  declarativos del dominio (nsmc.json, schema.k, morphisms/) que el
  crate consume — no son crates.

cargo check -p nakui-core: 0 errores.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/modules/nakui/core/src/lib.rs

@@ -0,0 +1,11 @@
+pub mod delta;
+pub mod drift;
+pub mod event_log;
+pub mod executor;
+pub mod graph;
+pub mod kcl_wrapper;
+pub mod manifest;
+pub mod rhai_executor;
+pub mod run;
+pub mod store;
+pub mod surreal_store;