feat(llvm-py): Major breakthrough in Python LLVM backend! 🎉

✅ Print and FileBox paths now working correctly
✅ Resolver simplified by removing overly aggressive fast-path optimization
✅ Both OFF/ON in compare_harness_on_off.sh now use Python version
✅ String handle propagation issues resolved

Key changes:
- Removed instruction reordering in llvm_builder.py (respecting MIR order)
- Resolver now more conservative but reliable
- compare_harness_on_off.sh updated to use Python backend for both paths

This marks a major milestone towards Phase 15 self-hosting with Python/llvmlite!

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Cargo.toml

@@ -29,9 +29,13 @@ plugins = ["dep:libloading"]
 # MIR instruction diet PoC flags (scaffolding only; off by default)
 mir_typeop_poc = []
 mir_refbarrier_unify_poc = []
-# Note: LLVM feature requires inkwell dependency and LLVM development libraries
-# LLVM 18 + inkwell 0.5.0 を使用
-llvm = ["dep:inkwell"]
+# LLVM features split
+# - llvm-harness: Python/llvmlite harness only（inkwell不要）
+# - llvm-inkwell-legacy: historical Rust/inkwell backend（参照用）
+# keep `llvm` as a compatibility alias to `llvm-harness`
+llvm-harness = []
+llvm-inkwell-legacy = ["dep:inkwell"]
+llvm = ["llvm-harness"]
 # (removed) Optional modular MIR builder feature
 cranelift-jit = [
   "dep:cranelift-codegen",