Phase 20.12b: quick green + structural cleanup

- Deprecations: add warn-once for nyash.toml (runtime::deprecations); apply in plugin loader v2 (singletons/method_resolver)
- Child env + runner hygiene: unify Stage‑3/quiet/disable-fallback env in test/runner; expand LLVM noise filters
- Docs/branding: prefer  and hako.toml in README.md/README.ja.md and smokes README
- VM: implement Map.clear in MIR interpreter (boxes_map)
- Stage‑B: gate bundle/alias/require smokes behind SMOKES_ENABLE_STAGEB; fix include cwd and resolve() call even for require-only cases
- Core‑Direct: gate rc boundary canary behind SMOKES_ENABLE_CORE_DIRECT
- Smokes: inject Stage‑3 and disable selfhost fallback for LLVM runs; filter using/* logs
- Quick profile: 168/168 PASS locally

This commit accelerates Phase 20.33 (80/20) by stabilizing quick suite, reducing noise, and gating heavy/experimental paths for speed.

src/runtime/deprecations.rs

@@ -0,0 +1,20 @@
+//! Deprecation warnings with "warn once" guards
+use std::sync::OnceLock;
+
+fn warn_once(flag: &'static OnceLock<()>, msg: &str) {
+    if flag.get().is_none() {
+        let _ = flag.set(());
+        eprintln!("{}", msg);
+    }
+}
+
+static NYASH_TOML_WARN_ONCE: OnceLock<()> = OnceLock::new();
+
+/// Warn once per process when nyash.toml is used while hako.toml is absent.
+pub fn warn_nyash_toml_used_once() {
+    warn_once(
+        &NYASH_TOML_WARN_ONCE,
+        "[deprecate] using nyash.toml; please rename to hako.toml",
+    );
+}
+

src/runtime/mod.rs

@@ -20,6 +20,7 @@ pub mod unified_registry;
 pub mod provider_lock;
 pub mod provider_verify;
 pub mod observe; // Lightweight observability flags (OOB etc.)
+pub mod deprecations; // Deprecation warnings with warn-once guards
 // pub mod plugin_box;  // legacy - 古いPluginBox
 // pub mod plugin_loader;  // legacy - Host VTable使用
 pub mod extern_registry; // ExternCall (env.*) 登録・診断用レジストリ

src/runtime/plugin_loader_v2/enabled/loader/singletons.rs

@@ -5,7 +5,13 @@ use crate::runtime::plugin_loader_v2::enabled::{errors, host_bridge, types};
 
 pub(super) fn prebirth_singletons(loader: &PluginLoaderV2) -> BidResult<()> {
     let config = loader.config.as_ref().ok_or(BidError::PluginError)?;
-    let cfg_path = loader.config_path.as_deref().unwrap_or("nyash.toml");
+    let cfg_path = loader
+        .config_path
+        .as_deref()
+        .unwrap_or_else(|| if std::path::Path::new("hako.toml").exists() { "hako.toml" } else { "nyash.toml" });
+    if cfg_path == "nyash.toml" && !std::path::Path::new("hako.toml").exists() {
+        crate::runtime::deprecations::warn_nyash_toml_used_once();
+    }
     let toml_content = errors::from_fs(std::fs::read_to_string(cfg_path))?;
     let toml_value: toml::Value = errors::from_toml(toml::from_str(&toml_content))?;
     for (lib_name, lib_def) in &config.libraries {
@@ -33,7 +39,13 @@ pub(super) fn ensure_singleton_handle(
     {
         return Ok(());
     }
-    let cfg_path = loader.config_path.as_deref().unwrap_or("nyash.toml");
+    let cfg_path = loader
+        .config_path
+        .as_deref()
+        .unwrap_or_else(|| if std::path::Path::new("hako.toml").exists() { "hako.toml" } else { "nyash.toml" });
+    if cfg_path == "nyash.toml" && !std::path::Path::new("hako.toml").exists() {
+        crate::runtime::deprecations::warn_nyash_toml_used_once();
+    }
     let toml_value: toml::Value =
         toml::from_str(&std::fs::read_to_string(cfg_path).map_err(|_| BidError::PluginError)?)
             .map_err(|_| BidError::PluginError)?;

src/runtime/plugin_loader_v2/enabled/method_resolver.rs

@@ -12,7 +12,13 @@ impl PluginLoaderV2 {
     pub(crate) fn resolve_method_id(&self, box_type: &str, method_name: &str) -> BidResult<u32> {
         // First try config mapping
         if let Some(cfg) = self.config.as_ref() {
-            let cfg_path = self.config_path.as_deref().unwrap_or("nyash.toml");
+            let cfg_path = self
+                .config_path
+                .as_deref()
+                .unwrap_or_else(|| if std::path::Path::new("hako.toml").exists() { "hako.toml" } else { "nyash.toml" });
+            if cfg_path == "nyash.toml" && !std::path::Path::new("hako.toml").exists() {
+                crate::runtime::deprecations::warn_nyash_toml_used_once();
+            }
 
             // Load and parse TOML
             let toml_content = std::fs::read_to_string(cfg_path).map_err(|_| BidError::PluginError)?;
@@ -70,7 +76,13 @@ impl PluginLoaderV2 {
     /// Check if a method returns a Result type
     pub fn method_returns_result(&self, box_type: &str, method_name: &str) -> bool {
         if let Some(cfg) = self.config.as_ref() {
-            let cfg_path = self.config_path.as_deref().unwrap_or("nyash.toml");
+            let cfg_path = self
+                .config_path
+                .as_deref()
+                .unwrap_or_else(|| if std::path::Path::new("hako.toml").exists() { "hako.toml" } else { "nyash.toml" });
+            if cfg_path == "nyash.toml" && !std::path::Path::new("hako.toml").exists() {
+                crate::runtime::deprecations::warn_nyash_toml_used_once();
+            }
 
             if let Ok(toml_content) = std::fs::read_to_string(cfg_path) {
                 if let Ok(toml_value) = toml::from_str::<toml::Value>(&toml_content) {
@@ -96,7 +108,13 @@ impl PluginLoaderV2 {
         method_name: &str,
     ) -> BidResult<(u32, u32, bool)> {
         let cfg = self.config.as_ref().ok_or(BidError::PluginError)?;
-        let cfg_path = self.config_path.as_deref().unwrap_or("nyash.toml");
+        let cfg_path = self
+            .config_path
+            .as_deref()
+            .unwrap_or_else(|| if std::path::Path::new("hako.toml").exists() { "hako.toml" } else { "nyash.toml" });
+        if cfg_path == "nyash.toml" && !std::path::Path::new("hako.toml").exists() {
+            crate::runtime::deprecations::warn_nyash_toml_used_once();
+        }
         let toml_value: toml::Value =
             toml::from_str(&std::fs::read_to_string(cfg_path).map_err(|_| BidError::PluginError)?)
                 .map_err(|_| BidError::PluginError)?;
@@ -124,4 +142,4 @@ pub(super) fn get_special_method_id(method_name: &str) -> Option<u32> {
         "fini" => Some(999),
         _ => None,
     }
-}
+}