feat(mir): Phase 25.1f完了 - Conservative PHI + ControlForm観測レイヤー

🎉 Conservative PHI Box理論による完全SSA構築

**Phase 7-B: Conservative PHI実装**
- 片方branchのみ定義変数に対応（emit_void使用）
- 全変数にPHI生成（Conservative Box理論）
- Stage-1 resolver全テスト緑化（3/3 PASS）

**Phase 25.1f: ControlForm観測レイヤー**
- LoopShape/IfShape/ControlForm構造定義
- Loop/If統一インターフェース実装
- debug_dump/debug_validate機能追加
- NYASH_CONTROL_FORM_TRACE環境変数対応

**主な変更**:
- src/mir/builder/phi.rs: Conservative PHI実装
- src/mir/control_form.rs: ControlForm構造（NEW）
- src/mir/loop_builder.rs: LoopForm v2デフォルト化

**テスト結果**:
✅ mir_stage1_using_resolver_min_fragment_verifies
✅ mir_stage1_using_resolver_full_collect_entries_verifies
✅ mir_parserbox_parse_program2_harness_parses_minimal_source

🤖 Generated with Claude Code
Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: ChatGPT <chatgpt@openai.com>

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

@@ -1,4 +1,3 @@
-use super::library;
 use super::PluginLoaderV2;
 use crate::bid::{BidError, BidResult};
 

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

@@ -6,8 +6,8 @@ mod specs;
 mod util;
 
 use super::host_bridge::BoxInvokeFn;
-use super::types::{LoadedPluginV2, PluginBoxMetadata, PluginBoxV2, PluginHandleInner};
-use crate::bid::{BidError, BidResult};
+use super::types::{LoadedPluginV2, PluginBoxMetadata, PluginHandleInner};
+use crate::bid::BidResult;
 use crate::box_trait::NyashBox;
 use crate::config::nyash_toml_v2::{LibraryDefinition, NyashConfigV2};
 use specs::LoadedBoxSpec;

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

@@ -1,4 +1,3 @@
-use super::specs;
 use super::PluginLoaderV2;
 use crate::bid::{BidError, BidResult};
 use crate::runtime::plugin_loader_v2::enabled::{errors, host_bridge, types};

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

@@ -18,6 +18,7 @@ pub(crate) struct LoadedBoxSpec {
 #[derive(Debug, Clone, Copy)]
 pub(crate) struct MethodSpec {
     pub(crate) method_id: u32,
+    #[allow(dead_code)]
     pub(crate) returns_result: bool,
 }
 

src/runtime/plugin_loader_v2/enabled/method_resolver.rs

@@ -5,7 +5,6 @@
 
 use crate::bid::{BidError, BidResult};
 use crate::runtime::plugin_loader_v2::enabled::PluginLoaderV2;
-use std::collections::HashMap;
 
 impl PluginLoaderV2 {
     /// Resolve a method ID for a given box type and method name
@@ -37,7 +36,7 @@ impl PluginLoaderV2 {
         // Fallback to TypeBox FFI spec
         if let Ok(map) = self.box_specs.read() {
             // Try direct lookup first
-            for ((lib, bt), spec) in map.iter() {
+            for ((_lib, bt), spec) in map.iter() {
                 if bt == box_type {
                     // Check methods map
                     if let Some(ms) = spec.methods.get(method_name) {
@@ -47,7 +46,7 @@ impl PluginLoaderV2 {
                     // Try resolve function
                     if let Some(res_fn) = spec.resolve_fn {
                         if let Ok(cstr) = std::ffi::CString::new(method_name) {
-                            let mid = unsafe { res_fn(cstr.as_ptr()) };
+                            let mid = res_fn(cstr.as_ptr());
                             if mid != 0 {
                                 return Ok(mid);
                             }
@@ -130,11 +129,13 @@ impl PluginLoaderV2 {
 }
 
 /// Helper functions for method resolution
+#[allow(dead_code)]
 pub(super) fn is_special_method(method_name: &str) -> bool {
     matches!(method_name, "birth" | "fini" | "toString")
 }
 
 /// Get default method IDs for special methods
+#[allow(dead_code)]
 pub(super) fn get_special_method_id(method_name: &str) -> Option<u32> {
     match method_name {
         "birth" => Some(1),

src/runtime/unified_registry.rs

@@ -8,7 +8,7 @@
 use crate::box_factory::builtin::BuiltinBoxFactory;
 #[cfg(feature = "plugins")]
 use crate::box_factory::plugin::PluginBoxFactory;
-use crate::box_factory::{UnifiedBoxRegistry, FactoryPolicy};
+use crate::box_factory::UnifiedBoxRegistry;
 use std::sync::{Arc, Mutex, OnceLock};
 
 /// Global registry instance