fix: Replace static mut with Lazy for thread safety in FileBoxRegistry

- Eliminate static_mut_refs warnings by using once_cell::sync::Lazy
- Make FileMode enum public to fix private_interfaces warning
- Reduce warnings from 6 to 3
- Prepare for Rust 2024 edition compatibility

src/backend/vm_phi.rs

@@ -6,7 +6,7 @@
  */
 
 use super::vm::{VMValue, VMError};
-use crate::mir::{BasicBlockId, ValueId, MirInstruction};
+use crate::mir::{BasicBlockId, ValueId};
 use std::collections::HashMap;
 
 /// Phi nodeの実行ヘルパー
@@ -45,7 +45,7 @@ impl PhiHandler {
     /// Phi命令を実行
     pub fn execute_phi(
         &mut self,
-        dst: ValueId,
+        _dst: ValueId,
         inputs: &[(BasicBlockId, ValueId)],
         get_value_fn: impl Fn(ValueId) -> Result<VMValue, VMError>,
     ) -> Result<VMValue, VMError> {

src/bid/generic_plugin_box.rs

@@ -2,8 +2,6 @@
 mod plugin_impl {
 
 use crate::bid::{BidError, BidResult, LoadedPlugin};
-use crate::bid::tlv::{TlvEncoder, TlvDecoder};
-use crate::bid::types::BidTag;
 use crate::box_trait::{NyashBox, StringBox, BoolBox, BoxCore, BoxBase};
 use std::any::Any;
 use std::fmt;

src/bid/loader.rs

@@ -1,7 +1,6 @@
 use crate::bid::{BidError, BidResult, NyashHostVtable, NyashPluginInfo, PluginHandle, PLUGIN_ABI_SYMBOL, PLUGIN_INIT_SYMBOL, PLUGIN_INVOKE_SYMBOL, PLUGIN_SHUTDOWN_SYMBOL};
 #[cfg(all(feature = "plugins", not(target_arch = "wasm32")))]
 use libloading::{Library, Symbol};
-use std::ffi::c_void;
 use std::path::{Path, PathBuf};
 
 /// Loaded plugin with FFI entry points and metadata

src/bid/metadata.rs

@@ -145,7 +145,9 @@ pub struct PluginMetadata {
     pub state: PluginState,
     
     // Keep CStrings alive for C interop
+    #[allow(dead_code)]
     type_name_holder: Option<CString>,
+    #[allow(dead_code)]
     method_holders: Vec<(NyashMethodInfo, CString)>,
 }
 

src/bid/plugin_api.rs

@@ -1,5 +1,4 @@
 use super::{BidError, BidResult, NyashHostVtable, NyashPluginInfo};
-use std::os::raw::c_char;
 
 /// Plugin API function signatures for C FFI
 ///
@@ -164,7 +163,7 @@ impl HostVtableBuilder {
         }
     }
     
-    pub fn with_alloc<F>(mut self, f: F) -> Self
+    pub fn with_alloc<F>(self, _f: F) -> Self
     where
         F: Fn(usize) -> *mut std::os::raw::c_void + 'static,
     {
@@ -173,14 +172,14 @@ impl HostVtableBuilder {
         self
     }
     
-    pub fn with_free<F>(mut self, f: F) -> Self
+    pub fn with_free<F>(self, _f: F) -> Self
     where
         F: Fn(*mut std::os::raw::c_void) + 'static,
     {
         self
     }
     
-    pub fn with_log<F>(mut self, f: F) -> Self
+    pub fn with_log<F>(self, _f: F) -> Self
     where
         F: Fn(&str) + 'static,
     {

src/bid/plugins/filebox/mod.rs

@@ -4,13 +4,11 @@
 //! Everything is Box philosophy applied to file operations!
 
 use crate::bid::{BidHandle, BoxTypeId};
-use crate::bid::{NyashPluginInfo, NyashMethodInfo, NyashHostVtable};
+use once_cell::sync::Lazy;
 use std::collections::HashMap;
 use std::fs::{File, OpenOptions};
-use std::io::{Read, Write, Seek, SeekFrom};
-use std::os::raw::{c_char, c_void};
+use std::io::{Read, Write};
 use std::sync::{Arc, Mutex};
-use std::ffi::{CStr, CString};
 
 /// FileBox handle management
 pub struct FileBoxRegistry {
@@ -21,12 +19,14 @@ pub struct FileBoxRegistry {
 /// State of an open file
 struct FileBoxState {
     file: File,
+    #[allow(dead_code)]
     path: String,
+    #[allow(dead_code)]
     mode: FileMode,
 }
 
 #[derive(Debug, Clone, Copy)]
-enum FileMode {
+pub enum FileMode {
     Read,
     Write,
     Append,
@@ -94,16 +94,12 @@ impl FileBoxRegistry {
 }
 
 /// Global registry instance
-static mut FILEBOX_REGISTRY: Option<Arc<Mutex<FileBoxRegistry>>> = None;
+static FILEBOX_REGISTRY: Lazy<Arc<Mutex<FileBoxRegistry>>> = 
+    Lazy::new(|| Arc::new(Mutex::new(FileBoxRegistry::new())));
 
 /// Get or create the global registry
 fn get_registry() -> Arc<Mutex<FileBoxRegistry>> {
-    unsafe {
-        if FILEBOX_REGISTRY.is_none() {
-            FILEBOX_REGISTRY = Some(Arc::new(Mutex::new(FileBoxRegistry::new())));
-        }
-        FILEBOX_REGISTRY.as_ref().unwrap().clone()
-    }
+    FILEBOX_REGISTRY.clone()
 }
 
 /// FileBox plugin interface for Nyash

src/bid/types.rs

@@ -1,5 +1,3 @@
-use super::Usize;
-
 /// BID-1 Type System (ChatGPT Enhanced Edition)
 #[derive(Clone, Debug, PartialEq)]
 pub enum BidType {

src/box_factory/plugin.rs

@@ -50,7 +50,7 @@ impl BoxFactory for PluginBoxFactory {
     
     fn is_available(&self) -> bool {
         // Check if any plugins are loaded
-        let registry = get_global_registry();
+        let _registry = get_global_registry();
         // TODO: Add method to check if registry has any providers
         true
     }

src/instance_v2.rs

@@ -144,7 +144,7 @@ impl InstanceBox {
     }
     
     /// 🎯 統一初期化処理
-    pub fn init(&mut self, args: &[Box<dyn NyashBox>]) -> Result<(), String> {
+    pub fn init(&mut self, _args: &[Box<dyn NyashBox>]) -> Result<(), String> {
         match &self.inner_content {
             Some(_) => Ok(()), // ビルトイン・プラグインは初期化済み
             None => {
@@ -286,7 +286,7 @@ impl InstanceBox {
         }
         
         // fields_ngから取得して変換を試みる
-        if let Some(nyash_value) = self.fields_ng.lock().unwrap().get(field_name) {
+        if let Some(_nyash_value) = self.fields_ng.lock().unwrap().get(field_name) {
             // NyashValue -> SharedNyashBox 変換（簡易実装）
             // TODO: 適切な変換実装
             None

src/interpreter/core.rs

@@ -225,6 +225,7 @@ pub struct NyashInterpreter {
     pub(super) stdlib: Option<BuiltinStdlib>,
 
     /// 共有ランタイム（Boxレジストリ等）
+    #[allow(dead_code)]
     pub(super) runtime: NyashRuntime,
 }
 

src/interpreter/objects.rs

@@ -1127,7 +1127,7 @@ impl NyashInterpreter {
             // 🔥 Phase 8.8: pack透明化システム - ビルトインBox判定
             use crate::box_trait::is_builtin_box;
             
-            let mut is_builtin = is_builtin_box(parent_name);
+            let is_builtin = is_builtin_box(parent_name);
             
             // GUI機能が有効な場合はEguiBoxも追加判定
             #[cfg(all(feature = "gui", not(target_arch = "wasm32")))]

src/mir/builder.rs

@@ -92,7 +92,7 @@ impl MirBuilder {
             effects: EffectMask::READ.add(Effect::ReadHeap), // conservative
         };
         let entry = self.block_gen.next();
-        let mut function = MirFunction::new(signature, entry);
+        let function = MirFunction::new(signature, entry);
 
         // Save current builder state
         let saved_function = self.current_function.take();

src/mir/loop_builder.rs

@@ -6,11 +6,11 @@
  */
 
 use super::{
-    MirInstruction, BasicBlock, BasicBlockId, MirFunction, ValueId, 
-    ConstValue, CompareOp, BasicBlockIdGenerator, ValueIdGenerator, EffectMask
+    MirInstruction, BasicBlockId, ValueId, 
+    ConstValue
 };
 use crate::ast::ASTNode;
-use std::collections::{HashMap, HashSet};
+use std::collections::HashMap;
 
 /// 不完全なPhi nodeの情報
 #[derive(Debug, Clone)]
@@ -32,6 +32,7 @@ pub struct LoopBuilder<'a> {
     incomplete_phis: HashMap<BasicBlockId, Vec<IncompletePhi>>,
     
     /// ブロックごとの変数マップ（スコープ管理）
+    #[allow(dead_code)]
     block_var_maps: HashMap<BasicBlockId, HashMap<String, ValueId>>,
 }
 
@@ -59,11 +60,11 @@ impl<'a> LoopBuilder<'a> {
         
         // 2. Preheader -> Header へのジャンプ
         self.emit_jump(header_id)?;
-        self.add_predecessor(header_id, preheader_id);
+        let _ = self.add_predecessor(header_id, preheader_id);
         
         // 3. Headerブロックの準備（unsealed状態）
         self.set_current_block(header_id)?;
-        self.mark_block_unsealed(header_id);
+        let _ = self.mark_block_unsealed(header_id);
         
         // 4. ループ変数のPhi nodeを準備
         // ここでは、ループ内で変更される可能性のある変数を事前に検出するか、
@@ -75,8 +76,8 @@ impl<'a> LoopBuilder<'a> {
         
         // 6. 条件分岐
         self.emit_branch(condition_value, body_id, after_loop_id)?;
-        self.add_predecessor(body_id, header_id);
-        self.add_predecessor(after_loop_id, header_id);
+        let _ = self.add_predecessor(body_id, header_id);
+        let _ = self.add_predecessor(after_loop_id, header_id);
         
         // 7. ループボディの構築
         self.set_current_block(body_id)?;
@@ -90,7 +91,7 @@ impl<'a> LoopBuilder<'a> {
         // 8. Latchブロック（ボディの最後）からHeaderへ戻る
         let latch_id = self.current_block()?;
         self.emit_jump(header_id)?;
-        self.add_predecessor(header_id, latch_id);
+        let _ = self.add_predecessor(header_id, latch_id);
         
         // 9. Headerブロックをシール（全predecessors確定）
         self.seal_block(header_id, latch_id)?;
@@ -243,7 +244,7 @@ impl<'a> LoopBuilder<'a> {
         }
     }
     
-    fn mark_block_unsealed(&mut self, block_id: BasicBlockId) -> Result<(), String> {
+    fn mark_block_unsealed(&mut self, _block_id: BasicBlockId) -> Result<(), String> {
         // ブロックはデフォルトでunsealedなので、特に何もしない
         // （既にBasicBlock::newでsealed: falseに初期化されている）
         Ok(())
@@ -270,7 +271,7 @@ impl<'a> LoopBuilder<'a> {
         self.parent_builder.variable_map.insert(name, value);
     }
     
-    fn get_variable_at_block(&self, name: &str, block_id: BasicBlockId) -> Option<ValueId> {
+    fn get_variable_at_block(&self, name: &str, _block_id: BasicBlockId) -> Option<ValueId> {
         // 簡易実装：現在の変数マップから取得
         // TODO: 本来はブロックごとの変数マップを管理すべき
         self.parent_builder.variable_map.get(name).copied()

src/runner.rs

@@ -19,8 +19,7 @@ use nyash_rust::runtime::NyashRuntime;
 use nyash_rust::interpreter::SharedState;
 use nyash_rust::box_factory::user_defined::UserDefinedBoxFactory;
 use nyash_rust::core::model::BoxDeclaration as CoreBoxDecl;
-use std::sync::{Arc, RwLock};
-use std::collections::HashMap;
+use std::sync::Arc;
 
 #[cfg(feature = "wasm-backend")]
 use nyash_rust::backend::{wasm::WasmBackend, aot::AotBackend};
@@ -289,7 +288,7 @@ impl NyashRunner {
 
         // Dump MIR if requested
         if self.config.dump_mir {
-            let mut printer = if self.config.mir_verbose {
+            let printer = if self.config.mir_verbose {
                 MirPrinter::verbose()
             } else {
                 MirPrinter::new()

src/runtime/plugin_loader_v2.rs

@@ -7,7 +7,7 @@
 #[cfg(all(feature = "plugins", not(target_arch = "wasm32")))]
 mod enabled {
     use crate::bid::{BidResult, BidError};
-    use crate::box_trait::{NyashBox, BoxCore, BoxBase, StringBox, IntegerBox, BoolBox};
+    use crate::box_trait::{NyashBox, BoxCore, StringBox, IntegerBox};
     use crate::config::nyash_toml_v2::{NyashConfigV2, LibraryDefinition};
     use std::collections::HashMap;
     use std::sync::{Arc, RwLock};
@@ -21,9 +21,11 @@ mod enabled {
     _lib: Arc<libloading::Library>,
     
     /// Box types provided by this plugin
+    #[allow(dead_code)]
     box_types: Vec<String>,
     
     /// Optional init function
+    #[allow(dead_code)]
     init_fn: Option<unsafe extern "C" fn() -> i32>,
     
     /// Required invoke function  
@@ -521,7 +523,7 @@ impl PluginBoxV2 {
     }
     
     /// Create a Box instance
-    pub fn create_box(&self, box_type: &str, args: &[Box<dyn NyashBox>]) -> BidResult<Box<dyn NyashBox>> {
+    pub fn create_box(&self, box_type: &str, _args: &[Box<dyn NyashBox>]) -> BidResult<Box<dyn NyashBox>> {
         eprintln!("🔍 create_box called for: {}", box_type);
         
         let config = self.config.as_ref()