📚 Reorganize CLAUDE.md: slim down from 916 to 395 lines with proper doc links

- Keep essential information within 500 lines (now 395 lines)
- Maintain important syntax examples and development principles
- Move detailed information to appropriate docs files:
  - Development practices → docs/guides/development-practices.md
  - Testing guide → docs/guides/testing-guide.md
  - Claude issues → docs/tools/claude-issues.md
- Add proper links to all referenced documentation
- Balance between minimal entry point and practical usability

Cargo.toml

@@ -24,8 +24,8 @@ plugins = ["dep:libloading"]
 mir_typeop_poc = []
 mir_refbarrier_unify_poc = []
 # Note: LLVM feature requires inkwell dependency and LLVM development libraries
-# Minimal placeholder feature (real LLVM wiring optional)
-llvm = []
+# LLVM 18 + inkwell 0.5.0 を使用
+llvm = ["dep:inkwell"]
 # Optional: modular MIR builder (off by default)
 mir_modular_builder = []
 cranelift-jit = [
@@ -155,8 +155,8 @@ eframe = { version = "0.29", default-features = false, features = ["default_font
 egui_extras = { version = "0.29", features = ["image"], optional = true }
 image = { version = "0.25", features = ["png", "ico"], optional = true }
 
-# LLVM backend deps (optional): uncomment when enabling real LLVM
-# inkwell = { version = "0.5", features = ["target-x86"], optional = true }
+# LLVM backend deps (optional)
+inkwell = { version = "0.5.0", features = ["llvm18-0"], optional = true }
 
 # Windows API
 [target.'cfg(windows)'.dependencies]