DECY Standard Library Support

RED PHASE: Built-in C standard library function prototypes

This crate provides ISO C99 §7 standard library function prototypes, enabling transpilation of C code that uses stdlib functions without requiring actual header files.

Pattern: EXTREME TDD - Test-First Development References: See docs/specifications/header-support-spec.md

Architecture

C Code → Prototype Injection → Parser → HIR → Rust
  ↓
#include <stdlib.h>
  ↓ (commented out by preprocessor)
Built-in prototypes injected
  ↓
malloc/free declarations available
  ↓
Parser succeeds!