feat: nyash.toml SSOT + using AST統合完了（12時間の戦い）

- nyash.tomlを唯一の真実（SSOT）として依存管理確立
- dev/ci/prodプロファイルによる段階的厳格化実装
- AST結合で宣言/式の曖昧性を根本解決
- Fail-Fast原則をCLAUDE.md/AGENTS.mdに明文化
- VM fallbackでもASTベース using有効化（NYASH_USING_AST=1）
- 静的メソッドの is_static=true 修正で解決安定化
- STATICブレークハック既定OFF化で堅牢性向上

🎉 usingシステム完全体への道筋確立！JSONライブラリ・Nyash VM開発が可能に

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

src/parser/declarations/static_box.rs

@@ -29,6 +29,15 @@ impl NyashParser {
         // Track last inserted method name to allow postfix catch/cleanup fallback parsing
         let mut last_method_name: Option<String> = None;
         while !self.match_token(&TokenType::RBRACE) && !self.is_at_end() {
+            // Tolerate blank lines between members
+            while self.match_token(&TokenType::NEWLINE) { self.advance(); }
+            let trace = std::env::var("NYASH_PARSER_TRACE_STATIC").ok().as_deref() == Some("1");
+            if trace {
+                eprintln!(
+                    "[parser][static-box] loop token={:?}",
+                    self.current_token().token_type
+                );
+            }
 
             // Fallback: method-level postfix catch/cleanup immediately following a method
             if crate::parser::declarations::box_def::members::postfix::try_parse_method_postfix_after_last_method(
@@ -45,8 +54,14 @@ impl NyashParser {
                 static_init = Some(body);
                 continue;
             } else if self.match_token(&TokenType::STATIC) {
-                // STRICT で top-level seam を検出した場合は while を抜ける
-                break;
+                // 互換用の暫定ガード（既定OFF）: using テキスト結合の継ぎ目で誤って 'static' が入った場合に
+                // ループを抜けて外側の '}' 消費に委ねる。既定では無効化し、文脈エラーとして扱う。
+                if std::env::var("NYASH_PARSER_SEAM_BREAK_ON_STATIC").ok().as_deref() == Some("1") {
+                    if std::env::var("NYASH_CLI_VERBOSE").ok().as_deref() == Some("1") {
+                        eprintln!("[parser][static-box][seam] encountered 'static' inside static box; breaking (compat shim)");
+                    }
+                    break;
+                }
             }
 
             // initブロックの処理（共通ヘルパに委譲）
@@ -69,6 +84,12 @@ impl NyashParser {
             }
         }
 
+        if std::env::var("NYASH_PARSER_TRACE_STATIC").ok().as_deref() == Some("1") {
+            eprintln!(
+                "[parser][static-box] closing '}}' at token={:?}",
+                self.current_token().token_type
+            );
+        }
         self.consume(TokenType::RBRACE)?;
 
         // 🔥 Static初期化ブロックから依存関係を抽出

src/parser/declarations/static_def/members.rs

@@ -56,6 +56,7 @@ pub(crate) fn try_parse_method_or_field(
     fields: &mut Vec<String>,
     last_method_name: &mut Option<String>,
 ) -> Result<bool, ParseError> {
+    let trace = std::env::var("NYASH_PARSER_TRACE_STATIC").ok().as_deref() == Some("1");
     // Allow NEWLINE(s) between identifier and '('
     if !p.match_token(&TokenType::LPAREN) {
         // Lookahead skipping NEWLINE to see if a '(' follows → treat as method head
@@ -65,11 +66,13 @@ pub(crate) fn try_parse_method_or_field(
             // Consume intervening NEWLINEs so current becomes '('
             while p.match_token(&TokenType::NEWLINE) { p.advance(); }
         } else {
+            if trace { eprintln!("[parser][static-box] field detected: {}", name); }
             // Field
             fields.push(name);
             return Ok(true);
         }
     }
+    if trace { eprintln!("[parser][static-box] method head detected: {}(..)", name); }
     // Method
     p.advance(); // consume '('
     let mut params = Vec::new();
@@ -84,14 +87,20 @@ pub(crate) fn try_parse_method_or_field(
     p.consume(TokenType::RPAREN)?;
     // Allow NEWLINE(s) between ')' and '{' of method body
     while p.match_token(&TokenType::NEWLINE) { p.advance(); }
-    let body = p.parse_block_statements()?;
+    // Parse method body; optionally use strict method-body guard when enabled
+    let body = if std::env::var("NYASH_PARSER_METHOD_BODY_STRICT").ok().as_deref() == Some("1") {
+        p.parse_method_body_statements()? 
+    } else {
+        p.parse_block_statements()?
+    };
     let body = wrap_method_body_with_postfix_if_any(p, body)?;
     // Construct method node
     let method = ASTNode::FunctionDeclaration {
         name: name.clone(),
         params,
         body,
-        is_static: false,
+        // Methods inside a static box are semantically static
+        is_static: true,
         is_override: false,
         span: crate::ast::Span::unknown(),
     };