feat(Phase 9.75j): Complete warning elimination - 106→0 warnings (100% improvement)

✨ Major code quality improvements:
• Fixed all unused variable and parameter warnings
• Added appropriate #[allow(dead_code)] annotations
• Renamed constants to follow Rust naming conventions
• Achieved completely warning-free codebase

🔧 Key changes:
• Parser expressions: Fixed arg_count and statement_count usage
• MIR modules: Added dead_code allows for future-use code
• Backend modules: Prefixed unused parameters with underscore
• Effect constants: Renamed 'read' to 'READ_ALIAS' for conventions

📊 Results:
• Before: 106 warnings (noisy build output)
• After: 0 warnings (clean build)
• Improvement: 100% warning reduction

🎯 This continues the bug fixing initiative "つづきのしゅうせいおねがいにゃ！"
from Phase 9.75i (birth() fixes, static methods, Copilot apps).

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

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

src/interpreter/methods/collection_methods.rs

@@ -8,7 +8,7 @@
  */
 
 use super::super::*;
-use crate::box_trait::{StringBox, IntegerBox, NyashBox, BoolBox};
+use crate::box_trait::{IntegerBox, NyashBox, BoolBox};
 use crate::boxes::{ArrayBox, MapBox};
 
 impl NyashInterpreter {

src/interpreter/methods/data_methods.rs

@@ -8,7 +8,7 @@
  */
 
 use super::super::*;
-use crate::box_trait::{NyashBox, StringBox, IntegerBox};
+use crate::box_trait::NyashBox;
 use crate::boxes::{buffer::BufferBox, JSONBox, RegexBox};
 
 impl NyashInterpreter {

src/interpreter/methods/mod.rs

@@ -25,9 +25,3 @@ pub mod p2p_methods;        // IntentBox, P2PBox
 pub mod http_methods;       // SocketBox, HTTPServerBox, HTTPRequestBox, HTTPResponseBox
 
 // Re-export methods for easy access
-pub use basic_methods::*;
-pub use collection_methods::*;
-pub use io_methods::*;
-pub use data_methods::*;
-pub use network_methods::*;
-pub use http_methods::*;

src/interpreter/methods/network_methods.rs

@@ -7,7 +7,7 @@
  */
 
 use super::super::*;
-use crate::box_trait::{NyashBox, StringBox};
+use crate::box_trait::NyashBox;
 use crate::boxes::{HttpClientBox, StreamBox};
 
 impl NyashInterpreter {

src/interpreter/methods/p2p_methods.rs

@@ -6,9 +6,8 @@
 use crate::interpreter::core::NyashInterpreter;
 use crate::interpreter::core::RuntimeError;
 use crate::ast::ASTNode;
-use crate::box_trait::{NyashBox, StringBox, BoolBox};
+use crate::box_trait::{NyashBox, StringBox};
 use crate::boxes::{IntentBox};
-use crate::method_box::MethodBox;
 
 impl NyashInterpreter {
     /// IntentBoxのメソッド実行 (RwLock版)