Initial commit: WAFER (WebAssembly Forth Engine in Rust)

Optimizing Forth 2012 compiler targeting WebAssembly with IR-based
compilation pipeline, multi-typed stack inference, subroutine threading,
and JIT/consolidation modes. Rust kernel with ~35 primitives and Forth
standard library for core/core-ext word sets.

crates/core/src/words/mod.rs

@@ -0,0 +1,19 @@
+//! Forth 2012 word set implementations.
+//!
+//! Each submodule implements one word set from the Forth 2012 standard.
+//! Words are implemented in Rust only when they require direct WASM instructions;
+//! most words are defined in Forth source files under `forth/`.
+
+// Word set modules will be added as each set is implemented:
+// pub mod core;
+// pub mod core_ext;
+// pub mod double;
+// pub mod exception;
+// pub mod floating;
+// pub mod locals;
+// pub mod string;
+// pub mod tools;
+// pub mod memory_alloc;
+// pub mod search_order;
+// pub mod file;
+// pub mod facility;