feat(phase90): Ring0Context fs/time/thread migration complete

Phase 90 完了: IO/fs/time/thread 系の Ring0 移行

**Phase 90-A: fs 系移行（7箇所）**
- FsApi trait 追加（6メソッド）
- StdFs 実装（std::fs ベース）
- IoError 拡張（4バリアント追加）
- 移行: strip.rs(4), dispatch.rs(1), mod.rs(3)

**Phase 90-B: io 系移行**
- Phase 88 完了済み（スキップ）

**Phase 90-C: time 系移行（3箇所）**
- TimeApi に elapsed() 追加
- 移行: selfhost_exe.rs(1), io.rs(1), plugin_loader_unified.rs(1)

**Phase 90-D: thread 系移行（2箇所）**
- ThreadApi trait 追加（sleep メソッド）
- StdThread 実装
- 移行: global_hooks.rs(1), plugin_loader_unified.rs(1)

**Phase 90-E: 統合テスト**
- ビルド成功（6 warnings, 0 errors）
- テスト: 522/554 passed (94.2%)
- 退行なし

**実装成果**:
- Ring0Context 拡張: fs, thread フィールド追加
- 総移行: 12箇所（fs: 7, time: 3, thread: 2）
- 移行率: fs(2.9%), time(2.1%), thread(5.4%)

**次のステップ**: Phase 91 (PluginHost/CoreServices skeleton)

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

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

src/runner/dispatch.rs

@@ -28,7 +28,9 @@ pub(crate) fn execute_file_with_backend(runner: &NyashRunner, filename: &str) {
     let groups = runner.config.as_groups();
     // Diagnostic/Exec: accept MIR JSON file direct (experimental; default OFF)
     if let Some(path) = groups.parser.mir_json_file.as_ref() {
-        match std::fs::read_to_string(path) {
+        // Phase 90-A: fs 系移行
+        let ring0 = crate::runtime::ring0::get_global_ring0();
+        match ring0.fs.read_to_string(std::path::Path::new(path)) {
             Ok(text) => {
                 // Try schema v1 first (preferred by emitter)
                 match crate::runner::json_v1_bridge::try_parse_v1_to_module(&text) {

src/runner/mod.rs

@@ -119,7 +119,9 @@ impl NyashRunner {
         }
         // Early: direct MIR JSON execution (no source file). Experimental diagnostics/exec.
         if let Some(path) = groups.parser.mir_json_file.as_ref() {
-            match std::fs::read_to_string(path) {
+            // Phase 90-A: fs 系移行
+            let ring0 = crate::runtime::ring0::get_global_ring0();
+            match ring0.fs.read_to_string(std::path::Path::new(path)) {
                 Ok(text) => match crate::runner::json_v1_bridge::try_parse_v1_to_module(&text) {
                     Ok(Some(module)) => {
                         let rc = self.execute_mir_module_quiet_exit(&module);
@@ -176,7 +178,9 @@ impl NyashRunner {
                     std::process::exit(0);
                 }
             } else if let Some(file) = groups.input.file.as_ref() {
-                match std::fs::read_to_string(file) {
+                // Phase 90-A: fs 系移行
+                let ring0 = crate::runtime::ring0::get_global_ring0();
+                match ring0.fs.read_to_string(std::path::Path::new(file)) {
                     Ok(code) => match crate::parser::NyashParser::parse_from_string(&code) {
                         Ok(ast) => {
                             let prog = crate::r#macro::ast_json::ast_to_json(&ast);
@@ -281,7 +285,9 @@ impl NyashRunner {
         }
         // Optional dependency tree bridge (log-only)
         if let Ok(dep_path) = std::env::var("NYASH_DEPS_JSON") {
-            match std::fs::read_to_string(&dep_path) {
+            // Phase 90-A: fs 系移行
+            let ring0 = crate::runtime::ring0::get_global_ring0();
+            match ring0.fs.read_to_string(std::path::Path::new(&dep_path)) {
                 Ok(s) => {
                     let bytes = s.as_bytes().len();
                     let mut root_info = String::new();

src/runner/modes/common_util/io.rs

@@ -1,7 +1,7 @@
 use std::io::Read;
 use std::process::{Command, Stdio};
 use std::thread::sleep;
-use std::time::{Duration, Instant};
+use std::time::Duration;
 
 pub struct ChildOutput {
     pub stdout: Vec<u8>,
@@ -19,7 +19,12 @@ pub fn spawn_with_timeout(mut cmd: Command, timeout_ms: u64) -> std::io::Result<
     let mut child = cmd.spawn()?;
     let ch_stdout = child.stdout.take();
     let ch_stderr = child.stderr.take();
-    let start = Instant::now();
+    // Phase 90-C: time 系移行
+    let ring0 = crate::runtime::ring0::get_global_ring0();
+    let start = ring0
+        .time
+        .monotonic_now()
+        .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e.to_string()))?;
     let mut timed_out = false;
     let mut exit_status: Option<std::process::ExitStatus> = None;
     loop {
@@ -29,7 +34,7 @@ pub fn spawn_with_timeout(mut cmd: Command, timeout_ms: u64) -> std::io::Result<
                 break;
             }
             None => {
-                if start.elapsed() >= Duration::from_millis(timeout_ms) {
+                if ring0.time.elapsed(start) >= Duration::from_millis(timeout_ms) {
                     let _ = child.kill();
                     let _ = child.wait();
                     timed_out = true;

src/runner/modes/common_util/resolve/strip.rs

@@ -547,7 +547,11 @@ pub fn resolve_prelude_paths_profiled(
         if !seen.insert(key.clone()) {
             return Ok(());
         }
-        let src = std::fs::read_to_string(&real_path)
+        // Phase 90-A: fs 系移行
+        let ring0 = crate::runtime::ring0::get_global_ring0();
+        let src = ring0
+            .fs
+            .read_to_string(std::path::Path::new(&real_path))
             .map_err(|e| format!("using: failed to read '{}': {}", real_path, e))?;
         let (_cleaned, nested, _nested_imports) =
             collect_using_and_strip(runner, &src, &real_path)?;
@@ -643,7 +647,11 @@ pub fn parse_preludes_to_asts(
                 prelude_path
             );
         }
-        let src = std::fs::read_to_string(prelude_path)
+        // Phase 90-A: fs 系移行
+        let ring0 = crate::runtime::ring0::get_global_ring0();
+        let src = ring0
+            .fs
+            .read_to_string(std::path::Path::new(prelude_path))
             .map_err(|e| format!("using: error reading {}: {}", prelude_path, e))?;
         let (clean_src, _nested, _nested_imports) =
             collect_using_and_strip(runner, &src, prelude_path)?;
@@ -890,7 +898,11 @@ pub fn merge_prelude_text(
         if !seen.insert(key.clone()) {
             return Ok(());
         }
-        let src = std::fs::read_to_string(path)
+        // Phase 90-A: fs 系移行
+        let ring0 = crate::runtime::ring0::get_global_ring0();
+        let src = ring0
+            .fs
+            .read_to_string(std::path::Path::new(path))
             .map_err(|e| format!("using: failed to read '{}': {}", path, e))?;
         let (_cleaned, nested, _nested_imports) = collect_using_and_strip(runner, &src, path)?;
         for n in nested.iter() {
@@ -926,7 +938,11 @@ pub fn merge_prelude_text(
 
     // Add preludes in DFS order
     for (idx, path) in prelude_paths.iter().enumerate() {
-        let content = std::fs::read_to_string(path)
+        // Phase 90-A: fs 系移行
+        let ring0 = crate::runtime::ring0::get_global_ring0();
+        let content = ring0
+            .fs
+            .read_to_string(std::path::Path::new(path))
             .map_err(|e| format!("using: failed to read '{}': {}", path, e))?;
 
         // Strip using lines from prelude and normalize

src/runner/modes/common_util/selfhost_exe.rs

@@ -1,7 +1,7 @@
 use std::io::Read;
 use std::process::Stdio;
 use std::thread::sleep;
-use std::time::{Duration, Instant};
+use std::time::Duration;
 
 /// Try external selfhost compiler EXE to parse Ny -> JSON v0 and return MIR module.
 /// Returns Some(module) on success, None on failure (timeout/invalid output/missing exe)
@@ -57,13 +57,15 @@ pub fn exe_try_parse_json_v0(filename: &str, timeout_ms: u64) -> Option<crate::m
     };
     let ch_stdout = child.stdout.take();
     let ch_stderr = child.stderr.take();
-    let start = Instant::now();
+    // Phase 90-C: time 系移行
+    let ring0 = crate::runtime::ring0::get_global_ring0();
+    let start = ring0.time.monotonic_now().ok()?;
     let mut timed_out = false;
     loop {
         match child.try_wait() {
             Ok(Some(_)) => break,
             Ok(None) => {
-                if start.elapsed() >= Duration::from_millis(timeout_ms) {
+                if ring0.time.elapsed(start) >= Duration::from_millis(timeout_ms) {
                     let _ = child.kill();
                     let _ = child.wait();
                     timed_out = true;