Phase 21.3 WIP: Hako Source Checker improvements - HC011/HC016/HC017 実装完了

主な変更:
- ✅ HC011 (dead methods) 実装・テスト緑
- ✅ HC016 (unused alias) 実装・テスト緑
- ✅ HC017 (non-ascii quotes) 実装完了
- 🔧 tokenizer/parser_core 強化（AST優先ルート）
- 🛡️ plugin_guard.rs 追加（stderr専用出力）
- 📋 テストインフラ整備（run_tests.sh改善）

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

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

src/backend/mir_interpreter/mod.rs

@@ -107,11 +107,88 @@ impl MirInterpreter {
     pub fn execute_module(&mut self, module: &MirModule) -> Result<Box<dyn NyashBox>, VMError> {
         // Snapshot functions for call resolution
         self.functions = module.functions.clone();
-        let func = module
-            .functions
-            .get("main")
-            .ok_or_else(|| VMError::InvalidInstruction("missing main".into()))?;
-        let ret = self.execute_function(func)?;
+
+        // Determine entry function with sensible fallbacks
+        // Priority:
+        //   1) NYASH_ENTRY env (exact), then basename before '/' if provided (e.g., "Main.main/0" → "Main.main")
+        //   2) "Main.main" if present
+        //   3) "main" (legacy/simple scripts)
+        let mut candidates: Vec<String> = Vec::new();
+        if let Ok(e) = std::env::var("NYASH_ENTRY") {
+            if !e.trim().is_empty() {
+                candidates.push(e.trim().to_string());
+            }
+        }
+        candidates.push("Main.main".to_string());
+        candidates.push("main".to_string());
+
+        // Try candidates in order
+        let mut chosen: Option<&nyash_rust::mir::MirFunction> = None;
+        for c in &candidates {
+            // exact
+            if let Some(f) = module.functions.get(c) {
+                chosen = Some(f);
+                break;
+            }
+            // if contains '/': try name before '/'
+            if let Some((head, _)) = c.split_once('/') {
+                if let Some(f) = module.functions.get(head) {
+                    chosen = Some(f);
+                    break;
+                }
+            }
+            // if looks like "Box.method": try plain "main" as last resort only when c endswith .main
+            if c.ends_with(".main") {
+                if let Some(f) = module.functions.get("main") {
+                    chosen = Some(f);
+                    break;
+                }
+            }
+        }
+
+        let func = match chosen {
+            Some(f) => f,
+            None => {
+                // Build helpful error message
+                let mut names: Vec<&String> = module.functions.keys().collect();
+                names.sort();
+                let avail = names.into_iter().take(12).cloned().collect::<Vec<_>>().join(", ");
+                let tried = candidates.join(", ");
+                let msg = format!(
+                    "entry function not found. searched: [{}]. available: [{}]. hint: define 'static box Main {{ method main(args){{ ... }} }}' or set NYASH_ENTRY=Name",
+                    tried, avail
+                );
+                return Err(VMError::InvalidInstruction(msg));
+            }
+        };
+
+        // Prepare arguments if the entry takes parameters (pass script args as ArrayBox)
+        let ret = if func.signature.params.len() == 0 {
+            self.execute_function(func)?
+        } else {
+            // Build argv from NYASH_SCRIPT_ARGS_JSON (set by CLI when using `--`) or NYASH_ARGV (JSON array)
+            let mut argv_list: Vec<String> = Vec::new();
+            if let Ok(s) = std::env::var("NYASH_SCRIPT_ARGS_JSON") {
+                if let Ok(v) = serde_json::from_str::<Vec<String>>(&s) { argv_list = v; }
+            } else if let Ok(s) = std::env::var("NYASH_ARGV") {
+                if let Ok(v) = serde_json::from_str::<Vec<String>>(&s) { argv_list = v; }
+            }
+            // Construct ArrayBox of StringBox
+            let array = crate::boxes::array::ArrayBox::new();
+            for a in argv_list.iter() {
+                let sb = crate::boxes::basic::StringBox::new(a);
+                let _ = array.push(Box::new(sb));
+            }
+            let boxed: Box<dyn crate::box_trait::NyashBox> = Box::new(array);
+            let arg0 = super::vm_types::VMValue::from_nyash_box(boxed);
+            // Fill remaining params with Void
+            let mut vm_args: Vec<super::vm_types::VMValue> = Vec::new();
+            vm_args.push(arg0);
+            for _ in 1..func.signature.params.len() {
+                vm_args.push(super::vm_types::VMValue::Void);
+            }
+            self.exec_function_inner(func, Some(&vm_args))?
+        };
         Ok(ret.to_nyash_box())
     }