diff --git a/src/config/env.rs b/src/config/env.rs
index 1049dcd7..56d9687d 100644
--- a/src/config/env.rs
+++ b/src/config/env.rs
@@ -2,6 +2,19 @@
 //!
 //! Consolidates NYASH_* environment variables across subsystems and
 //! optionally applies overrides from `nyash.toml`.
+//!
+//! # Modular Organization
+//!
+//! Environment flags are now organized into focused Box modules:
+//! - `joinir_flags` - JoinIR-related flags (30+ functions)
+//! - `mir_flags` - MIR-related flags (20+ functions)
+//! - `vm_backend_flags` - VM/Backend flags (15+ functions)
+//! - `parser_flags` - Parser flags (10+ functions)
+//! - `using_flags` - Using/namespace flags (10+ functions)
+//! - `verification_flags` - Verification flags (8+ functions)
+//! - `selfhost_flags` - Selfhost compiler flags (10+ functions)
+//!
+//! All functions are re-exported at the top level for backward compatibility.
 
 mod catalog;
 pub mod dump;
@@ -10,12 +23,31 @@ pub mod dump;
 pub mod joinir_dev;
 pub mod stage1;
 
+// New modular organization
+mod joinir_flags;
+mod mir_flags;
+mod vm_backend_flags;
+mod parser_flags;
+mod using_flags;
+mod verification_flags;
+mod selfhost_flags;
+
 pub use catalog::{env_vars, AppliesTo, EnvVarMeta};
 pub use dump::*;
 // Phase 124: hako_check exports removed (JoinIR-only consolidation)
 // pub use hako_check::*;
 pub use joinir_dev::*;
 pub use stage1::*;
+
+// Backward-compatible re-exports (NO BREAKING CHANGES!)
+pub use joinir_flags::*;
+pub use mir_flags::*;
+pub use vm_backend_flags::*;
+pub use parser_flags::*;
+pub use using_flags::*;
+pub use verification_flags::*;
+pub use selfhost_flags::*;
+
 use std::collections::BTreeMap;
 
 #[derive(Debug, Clone, Default)]
@@ -47,12 +79,10 @@ impl NyashEnv {
 // Global current env config (thread-safe)
 use once_cell::sync::OnceCell;
 use std::collections::HashSet;
-use std::sync::{Mutex, Once, RwLock};
+use std::sync::Mutex;
 
-static GLOBAL_ENV: OnceCell<RwLock<NyashEnv>> = OnceCell::new();
+static GLOBAL_ENV: OnceCell<std::sync::RwLock<NyashEnv>> = OnceCell::new();
 static WARNED_ALIASES: OnceCell<Mutex<HashSet<String>>> = OnceCell::new();
-static WARNED_JOINIR_CORE_OFF: Once = Once::new();
-// フェーズM.2: PHI_ON_GATED_WARNED削除（phi-legacy簡略化により不要）
 
 pub fn current() -> NyashEnv {
     if let Some(lock) = GLOBAL_ENV.get() {
@@ -70,7 +100,7 @@ pub fn set_current(cfg: NyashEnv) {
             return;
         }
     }
-    let _ = GLOBAL_ENV.set(RwLock::new(cfg));
+    let _ = GLOBAL_ENV.set(std::sync::RwLock::new(cfg));
 }
 
 /// Load overrides from nyash.toml `[env]` table and apply them to process env.
@@ -122,56 +152,6 @@ pub fn bootstrap_from_toml_env() {
     set_current(cur);
 }
 
-/// Get await maximum milliseconds, centralized here for consistency.
-pub fn await_max_ms() -> u64 {
-    std::env::var("NYASH_AWAIT_MAX_MS")
-        .ok()
-        .and_then(|s| s.parse().ok())
-        .unwrap_or(5000)
-}
-
-// ---- MIR PHI / PHI-less (edge-copy) mode ----
-/// Enable MIR PHI non-generation for Bridge compatibility mode only.
-/// フェーズM.2: MirBuilder/LoopBuilderでPHI統一済み、Bridge層の互換性制御のみ
-/// Default: PHI-ON (Phase 15 direction), override with NYASH_MIR_NO_PHI=1
-pub fn mir_no_phi() -> bool {
-    env_bool("NYASH_MIR_NO_PHI")
-}
-
-/// Allow verifier to skip SSA/dominance/merge checks for PHI-less MIR.
-pub fn verify_allow_no_phi() -> bool {
-    std::env::var("NYASH_VERIFY_ALLOW_NO_PHI").ok().as_deref() == Some("1") || mir_no_phi()
-}
-
-/// Enable strict edge-copy policy verification in PHI-off mode.
-/// When enabled, merge blocks must receive merged values via predecessor copies only,
-/// and the merge block itself must not introduce a self-copy to the merged destination.
-pub fn verify_edge_copy_strict() -> bool {
-    env_bool("NYASH_VERIFY_EDGE_COPY_STRICT")
-}
-
-/// Enforce purity of return blocks: no side-effecting instructions allowed before Return
-/// Default: OFF. Enable with NYASH_VERIFY_RET_PURITY=1 in dev/profiling sessions.
-pub fn verify_ret_purity() -> bool {
-    env_bool("NYASH_VERIFY_RET_PURITY")
-}
-
-/// Stage-B/selfhost 専用の dev verify トグル（SSA などの厳格チェックを一時緩和するためのスイッチ）
-/// Default: ON（現行挙動）。NYASH_STAGEB_DEV_VERIFY=0 で Stage-B 経路の dev verify をスキップ。
-pub fn stageb_dev_verify_enabled() -> bool {
-    env_flag("NYASH_STAGEB_DEV_VERIFY").unwrap_or(true)
-}
-
-// ---- LLVM harness toggle (llvmlite) ----
-pub fn llvm_use_harness() -> bool {
-    // Phase 15: デフォルトON（LLVMバックエンドはPythonハーネス使用）
-    // NYASH_LLVM_USE_HARNESS=0 で明示的に無効化可能
-    match std::env::var("NYASH_LLVM_USE_HARNESS").ok().as_deref() {
-        Some("0") | Some("false") | Some("off") => false,
-        _ => true, // デフォルト: ON（ハーネス使用）
-    }
-}
-
 /// Generic boolean env parser: accepts 1/true/on (case-insensitive) as true.
 pub fn env_bool(key: &str) -> bool {
     match std::env::var(key).ok() {
@@ -194,698 +174,13 @@ pub fn env_bool_default(key: &str, default: bool) -> bool {
     }
 }
 
-fn nyash_features_list() -> Option<Vec<String>> {
-    let raw = std::env::var("NYASH_FEATURES").ok()?;
-    let list: Vec<String> = raw
-        .split(',')
-        .filter_map(|s| {
-            let trimmed = s.trim();
-            if trimmed.is_empty() {
-                None
-            } else {
-                Some(trimmed.to_ascii_lowercase())
-            }
-        })
-        .collect();
-    if list.is_empty() {
-        None
-    } else {
-        Some(list)
-    }
-}
-
-fn feature_stage3_enabled() -> bool {
-    if let Some(list) = nyash_features_list() {
-        for item in list {
-            let normalized = item.replace(['-', '_'], "");
-            if normalized == "stage3" || normalized == "parserstage3" {
-                return true;
-            }
-        }
-    }
-    false
-}
-
-/// Global fail-fast policy for runtime fallbacks.
-/// Default: ON (true) to prohibit silent/different-route fallbacks in Rust layer.
-/// Set NYASH_FAIL_FAST=0 to temporarily allow legacy fallbacks during bring-up.
-pub fn fail_fast() -> bool {
-    env_bool_default("NYASH_FAIL_FAST", true)
-}
-
-// ---- Phase 29/30 JoinIR toggles ----
-/// JoinIR experiment mode. Required for JoinIR-related experimental paths.
-/// Set NYASH_JOINIR_EXPERIMENT=1 to enable.
-pub fn joinir_experiment_enabled() -> bool {
-    env_bool("NYASH_JOINIR_EXPERIMENT")
-}
-
-/// JoinIR core policy: **always ON** after LoopBuilder removal.
-/// - `NYASH_JOINIR_CORE` is deprecated（0 を指定しても警告して無視する）
-/// - JoinIR を OFF にするモードは提供しない（Fail-Fast 原則、フォールバックなし）
-pub fn joinir_core_enabled() -> bool {
-    if let Some(v) = env_flag("NYASH_JOINIR_CORE") {
-        if !v {
-            warn_joinir_core_off_ignored();
-        }
-    }
-    true
-}
-
-fn warn_joinir_core_off_ignored() {
-    WARNED_JOINIR_CORE_OFF.call_once(|| {
-        eprintln!(
-            "[deprecate/env] NYASH_JOINIR_CORE=0 is ignored; JoinIR core is always on (LoopBuilder is removed)"
-        );
-    });
-}
-
-/// JoinIR VM bridge mode. When enabled with NYASH_JOINIR_EXPERIMENT=1,
-/// specific functions can be executed via JoinIR → VM bridge instead of direct MIR → VM.
-/// Set NYASH_JOINIR_VM_BRIDGE=1 to enable.
-pub fn joinir_vm_bridge_enabled() -> bool {
-    joinir_core_enabled() && env_bool("NYASH_JOINIR_VM_BRIDGE")
-}
-
-/// JoinIR strict mode: when enabled, JoinIR 対象のフォールバックを禁止する。
-/// 既定OFF。NYASH_JOINIR_STRICT=1 のときのみ有効。
-pub fn joinir_strict_enabled() -> bool {
-    env_flag("NYASH_JOINIR_STRICT").unwrap_or(false)
-}
-
-/// JoinIR VM bridge debug output. Enables verbose logging of JoinIR→MIR conversion.
-/// Set NYASH_JOINIR_VM_BRIDGE_DEBUG=1 to enable.
-pub fn joinir_vm_bridge_debug() -> bool {
-    env_bool("NYASH_JOINIR_VM_BRIDGE_DEBUG")
-}
-
-/// JoinIR LLVM experiment mode. When enabled with NYASH_JOINIR_EXPERIMENT=1,
-/// enables experimental JoinIR→MIR'→LLVM path for specific functions (e.g., Main.skip/1).
-/// This is a dev-only toggle for testing PHI normalization via JoinIR in the LLVM path.
-/// Set NYASH_JOINIR_LLVM_EXPERIMENT=1 to enable.
-pub fn joinir_llvm_experiment_enabled() -> bool {
-    joinir_core_enabled() && env_bool("NYASH_JOINIR_LLVM_EXPERIMENT")
-}
-
-/// Phase 33: JoinIR If Select 実験の有効化
-/// Primary: HAKO_JOINIR_IF_SELECT (Phase 33-8+).
-pub fn joinir_if_select_enabled() -> bool {
-    // Core ON なら既定で有効化（JoinIR 本線化を優先）
-    if joinir_core_enabled() {
-        return true;
-    }
-    // Primary: HAKO_JOINIR_IF_SELECT
-    if let Some(v) = env_flag("HAKO_JOINIR_IF_SELECT") {
-        return v;
-    }
-    false
-}
-
-/// Phase 33-8: JoinIR Stage-1 rollout toggle
-/// Set HAKO_JOINIR_STAGE1=1 to enable JoinIR lowering for Stage-1 functions.
-pub fn joinir_stage1_enabled() -> bool {
-    // Primary: HAKO_JOINIR_STAGE1
-    if let Some(v) = env_flag("HAKO_JOINIR_STAGE1") {
-        return v;
-    }
-    false
-}
-
-/// Phase 33-8: JoinIR debug log level (0-3)
-/// - 0: No logs (default)
-/// - 1: Basic logs (which functions were lowered)
-/// - 2: Pattern matching details (CFG analysis)
-/// - 3: Full dump (all variables, all instructions)
-pub fn joinir_debug_level() -> u8 {
-    // Primary: HAKO_JOINIR_DEBUG
-    if let Ok(v) = std::env::var("HAKO_JOINIR_DEBUG") {
-        return v.parse().unwrap_or(0);
-    }
-    // Fallback: NYASH_JOINIR_DEBUG (deprecated)
-    if let Ok(v) = std::env::var("NYASH_JOINIR_DEBUG") {
-        warn_alias_once("NYASH_JOINIR_DEBUG", "HAKO_JOINIR_DEBUG");
-        return v.parse().unwrap_or(0);
-    }
-    0
-}
-
-/// Dev-only convenience switch to bundle experimental JoinIR knobs.
-/// - NYASH_JOINIR_DEV=1 enables
-/// - Otherwise inherits from joinir_debug_level()>0 (opt-in debug)
-pub fn joinir_dev_enabled() -> bool {
-    env_bool("NYASH_JOINIR_DEV") || joinir_debug_level() > 0
-}
-
-/// Phase 61-2: If-in-loop JoinIR dry-run有効化
-///
-/// `HAKO_JOINIR_IF_IN_LOOP_DRYRUN=1` でdry-runモードを有効化
-///
-/// dry-runモード:
-/// - JoinIR経路でPHI仕様を計算
-/// - PhiBuilderBox経路と比較
-/// - 実際のPHI生成はPhiBuilderBoxを使用（安全）
-pub fn joinir_if_in_loop_dryrun_enabled() -> bool {
-    env_bool("HAKO_JOINIR_IF_IN_LOOP_DRYRUN")
-}
-
-/// Phase 61-3: If-in-loop JoinIR本番経路有効化
-///
-/// `HAKO_JOINIR_IF_IN_LOOP_ENABLE=1` でJoinIR本番経路を有効化
-///
-/// 動作:
-/// - ON: JoinIR + IfInLoopPhiEmitter経路（PhiBuilderBox不使用）
-/// - OFF: PhiBuilderBox経路（既存フォールバック）
-///
-/// 前提条件:
-/// - JoinIR IfSelect 基盤（Phase 33）の有効化
-/// - dry-runモードとは独立（HAKO_JOINIR_IF_IN_LOOP_DRYRUN）
-///
-/// デフォルト: OFF（安全第一）
-pub fn joinir_if_in_loop_enable() -> bool {
-    env_bool("HAKO_JOINIR_IF_IN_LOOP_ENABLE")
-}
-
-/// Phase 61-4: ループ外If JoinIR経路有効化
-///
-/// `HAKO_JOINIR_IF_TOPLEVEL=1` でループ外IfのJoinIR経路を有効化
-///
-/// 動作:
-/// - ON: try_lower_if_to_joinir経路（if_form.rsで使用）
-/// - OFF: PhiBuilderBox経路（既存）
-///
-/// 前提条件:
-/// - HAKO_JOINIR_IF_SELECT=1（Phase 33基盤）
-///
-/// デフォルト: OFF（安全第一）
-pub fn joinir_if_toplevel_enabled() -> bool {
-    env_bool("HAKO_JOINIR_IF_TOPLEVEL")
-}
-
-/// Phase 61-4: ループ外If JoinIR dry-run有効化
-///
-/// `HAKO_JOINIR_IF_TOPLEVEL_DRYRUN=1` でdry-runモードを有効化
-///
-/// dry-runモード:
-/// - JoinIR経路を試行しログ出力
-/// - 実際のPHI生成は既存経路を使用（安全）
-pub fn joinir_if_toplevel_dryrun_enabled() -> bool {
-    env_bool("HAKO_JOINIR_IF_TOPLEVEL_DRYRUN")
-}
-
-// VM legacy by-name call fallback was removed (Phase 2 complete).
-// Phase 40-4.1: use_joinir_for_array_filter() removed (Route B now default).
-
-// ---- Phase 11.8 MIR cleanup toggles ----
-/// Core-13 minimal MIR mode toggle. Default ON unless NYASH_MIR_CORE13=0.
-pub fn mir_core13() -> bool {
-    match std::env::var("NYASH_MIR_CORE13").ok() {
-        Some(v) => {
-            let lv = v.to_ascii_lowercase();
-            !(lv == "0" || lv == "false" || lv == "off")
-        }
-        None => true,
-    }
-}
-pub fn mir_ref_boxcall() -> bool {
-    std::env::var("NYASH_MIR_REF_BOXCALL").ok().as_deref() == Some("1") || mir_core13()
-}
-pub fn mir_array_boxcall() -> bool {
-    std::env::var("NYASH_MIR_ARRAY_BOXCALL").ok().as_deref() == Some("1") || mir_core13()
-}
-pub fn mir_plugin_invoke() -> bool {
-    std::env::var("NYASH_MIR_PLUGIN_INVOKE").ok().as_deref() == Some("1")
-}
-pub fn plugin_only() -> bool {
-    std::env::var("NYASH_PLUGIN_ONLY").ok().as_deref() == Some("1")
-}
-
-/// Core-13 "pure" mode: only the 13 canonical ops are allowed (verifier rejects others).
-pub fn mir_core13_pure() -> bool {
-    env_bool("NYASH_MIR_CORE13_PURE")
-}
-
-// ---- Optimizer diagnostics ----
-pub fn opt_debug() -> bool {
-    std::env::var("NYASH_OPT_DEBUG").is_ok()
-}
-pub fn opt_diag() -> bool {
-    std::env::var("NYASH_OPT_DIAG").is_ok()
-}
-pub fn opt_diag_forbid_legacy() -> bool {
-    std::env::var("NYASH_OPT_DIAG_FORBID_LEGACY").is_ok()
-}
-pub fn opt_diag_fail() -> bool {
-    std::env::var("NYASH_OPT_DIAG_FAIL").is_ok()
-}
-
-// ---- Legacy compatibility (dev-only) ----
-/// Enable legacy InstanceBox fields (SharedNyashBox map) for compatibility.
-/// Default: OFF. Set NYASH_LEGACY_FIELDS_ENABLE=1 to materialize and use legacy fields.
-pub fn legacy_fields_enable() -> bool {
-    env_bool("NYASH_LEGACY_FIELDS_ENABLE")
-}
-
-// ---- GC/Runtime tracing (execution-affecting visibility) ----
-pub fn gc_trace() -> bool {
-    env_bool("NYASH_GC_TRACE")
-}
-pub fn gc_barrier_trace() -> bool {
-    env_bool("NYASH_GC_BARRIER_TRACE")
-}
-pub fn runtime_checkpoint_trace() -> bool {
-    env_bool("NYASH_RUNTIME_CHECKPOINT_TRACE")
-}
-pub fn gc_barrier_strict() -> bool {
-    std::env::var("NYASH_GC_BARRIER_STRICT").ok().as_deref() == Some("1")
-}
-
-/// Return 0 (off) to 3 (max) for `NYASH_GC_TRACE`.
-pub fn gc_trace_level() -> u8 {
-    match std::env::var("NYASH_GC_TRACE").ok().as_deref() {
-        Some("1") => 1,
-        Some("2") => 2,
-        Some("3") => 3,
-        Some(_) => 1,
-        None => 0,
-    }
-}
-
-// ---- GC mode and instrumentation ----
-/// Return current GC mode string (auto default = "rc+cycle").
-/// Allowed: "auto", "rc+cycle", "minorgen", "stw", "rc", "off"
-pub fn gc_mode() -> String {
-    match std::env::var("NYASH_GC_MODE").ok() {
-        Some(m) if !m.trim().is_empty() => m,
-        _ => "rc+cycle".to_string(),
-    }
-}
-/// Brief metrics emission (text)
-pub fn gc_metrics() -> bool {
-    std::env::var("NYASH_GC_METRICS").ok().as_deref() == Some("1")
-}
-/// JSON metrics emission (single line)
-pub fn gc_metrics_json() -> bool {
-    std::env::var("NYASH_GC_METRICS_JSON").ok().as_deref() == Some("1")
-}
-/// Optional allocation threshold; if Some(n) and exceeded, print warning
-pub fn gc_alloc_threshold() -> Option<u64> {
-    std::env::var("NYASH_GC_ALLOC_THRESHOLD").ok()?.parse().ok()
-}
-
-// ---- Cleanup (method-level postfix) policy toggles ----
-/// Allow `return` inside a cleanup block. Default: false (0)
-pub fn cleanup_allow_return() -> bool {
-    match std::env::var("NYASH_CLEANUP_ALLOW_RETURN").ok() {
-        Some(v) => {
-            let lv = v.to_ascii_lowercase();
-            !(lv == "0" || lv == "false" || lv == "off")
-        }
-        None => false,
-    }
-}
-
-/// Allow `throw` inside a cleanup block. Default: false (0)
-pub fn cleanup_allow_throw() -> bool {
-    match std::env::var("NYASH_CLEANUP_ALLOW_THROW").ok() {
-        Some(v) => {
-            let lv = v.to_ascii_lowercase();
-            !(lv == "0" || lv == "false" || lv == "off")
-        }
-        None => false,
-    }
-}
-
-/// Run a collection every N safepoints (if Some)
-pub fn gc_collect_sp_interval() -> Option<u64> {
-    std::env::var("NYASH_GC_COLLECT_SP").ok()?.parse().ok()
-}
-/// Run a collection when allocated bytes since last >= N (if Some)
-pub fn gc_collect_alloc_bytes() -> Option<u64> {
-    std::env::var("NYASH_GC_COLLECT_ALLOC").ok()?.parse().ok()
-}
-
-// ---- Rewriter flags (optimizer transforms)
-pub fn rewrite_debug() -> bool {
-    std::env::var("NYASH_REWRITE_DEBUG").ok().as_deref() == Some("1")
-}
-pub fn rewrite_safepoint() -> bool {
-    std::env::var("NYASH_REWRITE_SAFEPOINT").ok().as_deref() == Some("1")
-}
-pub fn rewrite_future() -> bool {
-    std::env::var("NYASH_REWRITE_FUTURE").ok().as_deref() == Some("1")
-}
-
-// ---- Phase 12: Nyash ABI (vtable) toggles ----
-pub fn abi_vtable() -> bool {
-    std::env::var("NYASH_ABI_VTABLE").ok().as_deref() == Some("1")
-}
-/// ABI strict diagnostics: missing vtable methods become errors when enabled.
-pub fn abi_strict() -> bool {
-    std::env::var("NYASH_ABI_STRICT").ok().as_deref() == Some("1")
-}
-
-// ---- Operator Boxes adopt defaults ----
-/// CompareOperator.apply adopt: default ON (prod/devともに採用)
-pub fn operator_box_compare_adopt() -> bool {
-    match std::env::var("NYASH_OPERATOR_BOX_COMPARE_ADOPT")
-        .ok()
-        .as_deref()
-        .map(|v| v.to_ascii_lowercase())
-    {
-        Some(ref s) if s == "0" || s == "false" || s == "off" => false,
-        Some(ref s) if s == "1" || s == "true" || s == "on" => true,
-        _ => true, // default ON
-    }
-}
-/// AddOperator.apply adopt: default OFF（順次昇格のため）
-pub fn operator_box_add_adopt() -> bool {
-    match std::env::var("NYASH_OPERATOR_BOX_ADD_ADOPT")
-        .ok()
-        .as_deref()
-        .map(|v| v.to_ascii_lowercase())
-    {
-        Some(ref s) if s == "0" || s == "false" || s == "off" => false,
-        _ => true, // default ON (promoted after validation)
-    }
-}
-
-// ---- Null/Missing Boxes (dev-only observe → adopt) ----
-/// Enable NullBox/MissingBox observation path (no behavior change by default).
-/// Default: OFF. Turn ON with `NYASH_NULL_MISSING_BOX=1`. May be auto-enabled in --dev later.
-pub fn null_missing_box_enabled() -> bool {
-    std::env::var("NYASH_NULL_MISSING_BOX").ok().as_deref() == Some("1")
-}
-/// Strict null policy for operators (when enabled): null in arithmetic/compare is an error.
-/// Default: OFF (null propagates). Effective only when `null_missing_box_enabled()` is true.
-pub fn null_strict() -> bool {
-    std::env::var("NYASH_NULL_STRICT").ok().as_deref() == Some("1")
-}
-
-// ---- Phase 12: thresholds and routing policies ----
-// ---- Runner/CLI common toggles (hot-path centralization)
-pub fn cli_verbose() -> bool {
-    cli_verbose_level() > 0
-}
-pub fn enable_using() -> bool {
-    // Phase 15: デフォルトON（using systemはメイン機能）
-    // NYASH_ENABLE_USING=0 で明示的に無効化可能。HAKO_ENABLE_USING は互換のため受理（警告）。
-    match std::env::var("NYASH_ENABLE_USING").ok().as_deref() {
-        Some("0") | Some("false") | Some("off") => return false,
-        Some(_) => return true,
-        None => {}
-    }
-    // Fallback to alias
-    if let Some(v) = std::env::var("HAKO_ENABLE_USING").ok() {
-        warn_alias_once("HAKO_ENABLE_USING", "NYASH_ENABLE_USING");
-        let lv = v.to_ascii_lowercase();
-        return !(lv == "0" || lv == "false" || lv == "off");
-    }
-    true // default ON
-}
-
-// ---- Using profiles (dev|ci|prod) ----
-/// Return using profile string; default is "dev".
-pub fn using_profile() -> String {
-    std::env::var("NYASH_USING_PROFILE").unwrap_or_else(|_| "dev".to_string())
-}
-/// True when using profile is prod (disables some dev-only behaviors).
-pub fn using_is_prod() -> bool {
-    using_profile().eq_ignore_ascii_case("prod")
-}
-/// True when using profile is ci.
-pub fn using_is_ci() -> bool {
-    using_profile().eq_ignore_ascii_case("ci")
-}
-/// True when using profile is dev (default).
-pub fn using_is_dev() -> bool {
-    using_profile().eq_ignore_ascii_case("dev")
-}
-/// Allow `using "path"` statements in source (dev-only by default).
-pub fn allow_using_file() -> bool {
-    // SSOT 徹底: 全プロファイルで既定禁止（nyash.toml を唯一の真実に）
-    // 明示オーバーライドでのみ許可（開発用緊急時）
-    match std::env::var("NYASH_ALLOW_USING_FILE").ok().as_deref() {
-        Some("1") | Some("true") | Some("on") => true,
-        _ => false,
-    }
-}
-/// Determine whether AST prelude merge for `using` is enabled.
-/// Precedence:
-/// 1) Explicit env `NYASH_USING_AST` = 1/true/on → enabled, = 0/false/off → disabled
-/// 2) Default by profile: dev/ci → ON, prod → OFF
-pub fn using_ast_enabled() -> bool {
-    match std::env::var("NYASH_USING_AST")
-        .ok()
-        .as_deref()
-        .map(|v| v.to_ascii_lowercase())
-    {
-        Some(ref s) if s == "1" || s == "true" || s == "on" => true,
-        Some(ref s) if s == "0" || s == "false" || s == "off" => false,
-        _ => !using_is_prod(), // dev/ci → true, prod → false
-    }
-}
-/// Policy: allow VM to fallback-dispatch user Instance BoxCall (dev only by default).
-/// - prod: default false (disallow)
-/// - dev/ci: default true (allow, with WARN)
-/// Override with NYASH_VM_USER_INSTANCE_BOXCALL={0|1}
-pub fn vm_allow_user_instance_boxcall() -> bool {
-    match std::env::var("NYASH_VM_USER_INSTANCE_BOXCALL")
-        .ok()
-        .as_deref()
-        .map(|v| v.to_ascii_lowercase())
-    {
-        Some(ref s) if s == "0" || s == "false" || s == "off" => false,
-        Some(ref s) if s == "1" || s == "true" || s == "on" => true,
-        _ => !using_is_prod(),
-    }
-}
-// Legacy resolve_fix_braces() removed (Phase 15 cleanup)
-// AST-based integration handles syntax properly without text-level brace fixing
-pub fn vm_use_py() -> bool {
-    std::env::var("NYASH_VM_USE_PY").ok().as_deref() == Some("1")
-}
-pub fn pipe_use_pyvm() -> bool {
-    std::env::var("NYASH_PIPE_USE_PYVM").ok().as_deref() == Some("1")
-}
-/// (Deprecated) use dispatch-based VM route; currently disabled.
-pub fn vm_use_dispatch() -> bool {
-    false
-}
-/// Force VM fallback interpreter route (dev-only escape hatch).
-pub fn vm_use_fallback() -> bool {
-    std::env::var("NYASH_VM_USE_FALLBACK").ok().as_deref() == Some("1")
-}
-/// Trace VM route selection decisions.
-pub fn vm_route_trace() -> bool {
-    std::env::var("NYASH_VM_ROUTE_TRACE").ok().as_deref() == Some("1")
-}
-
-// Self-host compiler knobs
-pub fn ny_compiler_timeout_ms() -> u64 {
-    std::env::var("NYASH_NY_COMPILER_TIMEOUT_MS")
-        .ok()
-        .and_then(|s| s.parse().ok())
-        .unwrap_or(2000)
-}
-/// Emit-only flag for selfhost compiler (default ON to avoid execution).
-pub fn ny_compiler_emit_only() -> bool {
-    std::env::var("NYASH_NY_COMPILER_EMIT_ONLY").unwrap_or_else(|_| "1".to_string()) == "1"
-}
-/// Path to external selfhost compiler executable (when enabled).
-pub fn use_ny_compiler_exe() -> bool {
-    std::env::var("NYASH_USE_NY_COMPILER_EXE").ok().as_deref() == Some("1")
-}
-/// Path to external selfhost compiler executable (when enabled).
-pub fn ny_compiler_exe_path() -> Option<String> {
-    std::env::var("NYASH_NY_COMPILER_EXE_PATH").ok()
-}
-/// Pass `-- --min-json` to child selfhost compiler (minimal JSON output).
-pub fn ny_compiler_min_json() -> bool {
-    std::env::var("NYASH_NY_COMPILER_MIN_JSON").ok().as_deref() == Some("1")
-}
-/// When true, child reads tmp/ny_parser_input.ny instead of stdin/source text.
-pub fn selfhost_read_tmp() -> bool {
-    std::env::var("NYASH_SELFHOST_READ_TMP").ok().as_deref() == Some("1")
-}
-/// Pass `-- --stage3` to child selfhost compiler to allow Stage-3 surface.
-pub fn ny_compiler_stage3() -> bool {
-    std::env::var("NYASH_NY_COMPILER_STAGE3").ok().as_deref() == Some("1")
-}
-/// Core (Rust) parser Stage-3 gate (default ON).
-/// Precedence:
-/// 1) NYASH_FEATURES contains `stage3`/`parser-stage3`
-/// 2) Legacy env aliases (NYASH_PARSER_STAGE3 / HAKO_PARSER_STAGE3)
-/// 3) Default true (Stage-3 is standard syntax)
-pub fn parser_stage3_enabled() -> bool {
-    if feature_stage3_enabled() {
-        return true;
-    }
-    if let Some(v) = env_flag("NYASH_PARSER_STAGE3") {
-        warn_alias_once("NYASH_PARSER_STAGE3", "NYASH_FEATURES=stage3");
-        return v;
-    }
-    if let Some(v) = env_flag("HAKO_PARSER_STAGE3") {
-        warn_alias_once("HAKO_PARSER_STAGE3", "NYASH_FEATURES=stage3");
-        return v;
-    }
-    true
-}
-
-#[deprecated(note = "Use parser_stage3_enabled() instead")]
-pub fn parser_stage3() -> bool {
-    parser_stage3_enabled()
-}
-
-/// Parser gate for Block‑Postfix Catch acceptance
-/// Enabled when either NYASH_BLOCK_CATCH=1 or Stage‑3 gate is on.
-/// Phase 15.5 allows parsing a standalone `{ ... }` block optionally followed by
-/// a single `catch (...) { ... }` and/or `finally { ... }`, which is folded into
-/// ASTNode::TryCatch with the preceding block as the try body.
-pub fn block_postfix_catch() -> bool {
-    std::env::var("NYASH_BLOCK_CATCH").ok().as_deref() == Some("1") || parser_stage3_enabled()
-}
-
-/// Bridge lowering: use Result-style try/throw lowering instead of MIR Catch/Throw
-/// When on, try/catch is lowered using structured blocks and direct jumps,
-/// without emitting MIR Throw/Catch. The thrown value is routed to catch via
-/// block parameters (PHI-off uses edge-copy).
-pub fn try_result_mode() -> bool {
-    std::env::var("NYASH_TRY_RESULT_MODE").ok().as_deref() == Some("1")
-}
-
-/// Parser gate for method-level postfix catch/finally acceptance on method definitions.
-/// Enabled when either NYASH_METHOD_CATCH=1 or Stage‑3 gate is on.
-pub fn method_catch() -> bool {
-    std::env::var("NYASH_METHOD_CATCH").ok().as_deref() == Some("1") || parser_stage3_enabled()
-}
-
-/// Entry policy: allow top-level `main` resolution in addition to `Main.main`.
-/// Default: true (prefer `Main.main` when both exist; otherwise accept `main`).
-pub fn entry_allow_toplevel_main() -> bool {
-    match std::env::var("NYASH_ENTRY_ALLOW_TOPLEVEL_MAIN").ok() {
-        Some(v) => {
-            let v = v.to_ascii_lowercase();
-            v == "1" || v == "true" || v == "on"
-        }
-        None => true,
-    }
-}
-
-/// Parser gate for expression-level postfix catch/cleanup acceptance.
-/// Enabled when Stage-3 gate is on (NYASH_FEATURES=stage3 or legacy aliases). Separate gate can
-/// be introduced in future if needed, but we keep minimal toggles now.
-pub fn expr_postfix_catch() -> bool {
-    parser_stage3_enabled()
-}
-/// Parser gate for Unified Members (stored/computed/once/birth_once).
-/// Default: ON during Phase-15 (set NYASH_ENABLE_UNIFIED_MEMBERS=0|false|off to disable).
-pub fn unified_members() -> bool {
-    match std::env::var("NYASH_ENABLE_UNIFIED_MEMBERS").ok() {
-        Some(v) => {
-            let lv = v.to_ascii_lowercase();
-            !(lv == "0" || lv == "false" || lv == "off")
-        }
-        None => true,
-    }
-}
-pub fn ny_compiler_child_args() -> Option<String> {
-    // Pass-through args to selfhost child (space-separated).
-    std::env::var("NYASH_NY_COMPILER_CHILD_ARGS").ok()
-}
-pub fn ny_compiler_use_tmp_only() -> bool {
-    std::env::var("NYASH_NY_COMPILER_USE_TMP_ONLY")
-        .ok()
-        .as_deref()
-        == Some("1")
-}
-
-/// Use Python MVP harness for Ny compiler (NYASH_NY_COMPILER_USE_PY=1).
-pub fn ny_compiler_use_py() -> bool {
-    std::env::var("NYASH_NY_COMPILER_USE_PY").ok().as_deref() == Some("1")
-}
-
-/// Macro pre-expand mode for selfhost (NYASH_MACRO_SELFHOST_PRE_EXPAND).
-/// Returns "1", "auto", or None.
-pub fn macro_selfhost_pre_expand() -> Option<String> {
-    std::env::var("NYASH_MACRO_SELFHOST_PRE_EXPAND").ok()
-}
-
-/// ScopeBox enable flag (NYASH_SCOPEBOX_ENABLE=1).
-pub fn scopebox_enable() -> bool {
-    std::env::var("NYASH_SCOPEBOX_ENABLE").ok().as_deref() == Some("1")
-}
-
-/// LoopForm normalize flag (NYASH_LOOPFORM_NORMALIZE=1).
-pub fn loopform_normalize() -> bool {
-    std::env::var("NYASH_LOOPFORM_NORMALIZE").ok().as_deref() == Some("1")
-}
-
-/// Dev-only escape hatch: force inline selfhost path (NYASH_SELFHOST_INLINE_FORCE=1).
-pub fn selfhost_inline_force() -> bool {
-    std::env::var("NYASH_SELFHOST_INLINE_FORCE").ok().as_deref() == Some("1")
-}
-
-/// Unicode decode toggle for string literals (\uXXXX, optional surrogate pairs).
-/// Enabled when either HAKO_PARSER_DECODE_UNICODE=1 or NYASH_PARSER_DECODE_UNICODE=1.
-/// Default: OFF (for strict backward compatibility).
-pub fn parser_decode_unicode() -> bool {
-    env_flag("HAKO_PARSER_DECODE_UNICODE")
-        .or_else(|| env_flag("NYASH_PARSER_DECODE_UNICODE"))
-        .unwrap_or(false)
-}
-fn env_flag(var: &str) -> Option<bool> {
+pub(crate) fn env_flag(var: &str) -> Option<bool> {
     std::env::var(var).ok().map(|v| {
         let lv = v.to_ascii_lowercase();
         lv == "1" || lv == "true" || lv == "on"
     })
 }
 
-pub fn nyvm_core_wrapper() -> bool {
-    env_flag("HAKO_NYVM_CORE")
-        .or_else(|| env_flag("NYASH_NYVM_CORE"))
-        .unwrap_or(false)
-}
-
-pub fn nyvm_bridge_inject_singleton() -> bool {
-    env_flag("HAKO_BRIDGE_INJECT_SINGLETON")
-        .or_else(|| env_flag("NYASH_BRIDGE_INJECT_SINGLETON"))
-        .unwrap_or(false)
-}
-
-pub fn nyvm_bridge_early_phi_materialize() -> bool {
-    env_flag("HAKO_BRIDGE_EARLY_PHI_MATERIALIZE")
-        .or_else(|| env_flag("NYASH_BRIDGE_EARLY_PHI_MATERIALIZE"))
-        .unwrap_or(false)
-}
-
-pub fn nyvm_v1_downconvert() -> bool {
-    env_flag("HAKO_NYVM_V1_DOWNCONVERT")
-        .or_else(|| env_flag("NYASH_NYVM_V1_DOWNCONVERT"))
-        .unwrap_or(false)
-}
-
-/// Gate‑C(Core) strict OOB handling: when enabled, any observed OOB tag
-/// (emitted by runtime during ArrayBox get/set with HAKO_OOB_STRICT=1) should
-/// cause non‑zero exit at the end of JSON→VM execution.
-pub fn oob_strict_fail() -> bool {
-    env_flag("HAKO_OOB_STRICT_FAIL")
-        .or_else(|| env_flag("NYASH_OOB_STRICT_FAIL"))
-        .unwrap_or(false)
-}
-
-/// Primary verification route: return true when Hakorune VM is requested as primary.
-/// Accepts HAKO_VERIFY_PRIMARY=hakovm (preferred) or legacy HAKO_ROUTE_HAKOVM=1 (deprecated, warns).
-pub fn verify_primary_is_hakovm() -> bool {
-    if std::env::var("HAKO_VERIFY_PRIMARY").ok().as_deref() == Some("hakovm") {
-        return true;
-    }
-    if env_bool("HAKO_ROUTE_HAKOVM") {
-        warn_alias_once("HAKO_ROUTE_HAKOVM", "HAKO_VERIFY_PRIMARY=hakovm");
-        return true;
-    }
-    false
-}
-
 pub(crate) fn warn_alias_once(alias: &str, primary: &str) {
     let set = WARNED_ALIASES.get_or_init(|| Mutex::new(HashSet::new()));
     if let Ok(mut s) = set.lock() {
@@ -898,51 +193,3 @@ pub(crate) fn warn_alias_once(alias: &str, primary: &str) {
         }
     }
 }
-
-// ---- ENV consolidation helpers (Phase 21.10/22.1) ----
-/// LLVM opt level (primary: NYASH_LLVM_OPT_LEVEL; alias: HAKO_LLVM_OPT_LEVEL)
-/// Returns string level (e.g., "0", "1", ...). Default: "0" when unset.
-pub fn llvm_opt_level() -> String {
-    if let Some(v) = std::env::var("NYASH_LLVM_OPT_LEVEL").ok() {
-        return v;
-    }
-    if let Some(v) = std::env::var("HAKO_LLVM_OPT_LEVEL").ok() {
-        warn_alias_once("HAKO_LLVM_OPT_LEVEL", "NYASH_LLVM_OPT_LEVEL");
-        return v;
-    }
-    "0".to_string()
-}
-
-/// Gate‑C(Core) route request (primary: NYASH_GATE_C_CORE; alias: HAKO_GATE_C_CORE)
-pub fn gate_c_core() -> bool {
-    if env_bool("NYASH_GATE_C_CORE") {
-        return true;
-    }
-    if env_bool("HAKO_GATE_C_CORE") {
-        warn_alias_once("HAKO_GATE_C_CORE", "NYASH_GATE_C_CORE");
-        return true;
-    }
-    false
-}
-
-/// Consolidated toggle for selfhost NY compiler pipeline.
-/// Primary: NYASH_USE_NY_COMPILER=0|1（明示指定のみ有効）。Legacy disables accepted (with warning):
-/// NYASH_DISABLE_NY_COMPILER/HAKO_DISABLE_NY_COMPILER (any true value disables).
-pub fn use_ny_compiler() -> bool {
-    // Primary knob takes precedence when explicitly set
-    if let Some(v) = std::env::var("NYASH_USE_NY_COMPILER").ok() {
-        let lv = v.trim().to_ascii_lowercase();
-        return lv == "1" || lv == "true" || lv == "on";
-    }
-    // Legacy disable aliases — if any is true, treat as disabled and warn
-    if env_bool("NYASH_DISABLE_NY_COMPILER") {
-        warn_alias_once("NYASH_DISABLE_NY_COMPILER", "NYASH_USE_NY_COMPILER=0");
-        return false;
-    }
-    if env_bool("HAKO_DISABLE_NY_COMPILER") {
-        warn_alias_once("HAKO_DISABLE_NY_COMPILER", "NYASH_USE_NY_COMPILER=0");
-        return false;
-    }
-    // Phase 25.1b: Default OFF（selfhost NY compiler は明示 opt-in のみ）
-    false
-}