diff --git a/docs/todo-summary.md b/docs/todo-summary.md
index e062eea2..aea350e0 100644
--- a/docs/todo-summary.md
+++ b/docs/todo-summary.md
@@ -99,8 +99,6 @@
 | 226 | 🚀 Tier 1 | **fmt baseline cleanup + `cargo fmt --check` gate 導入 + rustfmt 固定 (PR #224 セッション合意)** | todo13.md | M | なし (fmt enforcement がリポジトリに皆無で workspace 29 ファイルが rustfmt-clean でないドリフト蓄積。(A) `cargo fmt --all` 一括正規化 → (B) fmt --check を Stop/push gate に追加 → (C) rust-toolchain.toml で rustfmt 固定、の順。file_length plan と同型「clean baseline → gate」) |
 | 227 | 🚀 Tier 1 | **rule⑬: 非テストコードでの理由なし `#[allow(...)]` 禁止 custom lint (PR #224 セッション合意)** | todo13.md | S | なし (`#[allow]` = lint の握り潰し、既存 swallowed-error 系 rule③/④/⑩ と同 philosophy。justification マーカー無しの `#[allow(...)]` を warning 検出、test code 除外方式は着手時判断、rule_test_coverage_check で positive/negative test 機械強制) |
 | 228 | 🔧 Tier 2 | **`rate_limit_signal::cr_clean` の regression test (PR #224 post-merge-feedback T2-1 採用)** | todo13.md | S | なし (Fix 3 で拡張した `unresolved_threads` / `new_comments` / `actionable_comments` 3 field の clean 判定の回帰防止、None/境界ケース網羅、silent-clean 誤認の保護) |
-| 229 | 🔧 Tier 2 | **共有 `env_override_lock` helper 抽出 — 並列 test の state file override 競合解消 (PR #224 post-merge-feedback T2-2 採用)** | todo13.md | S | なし (複数 test module の独立 static LOCK を単一化。memory `feedback_test_dry_antipattern` の per-module 複製原則との境界 = serialization primitive は単一必須、要ユーザー確認) |
-| 230 | 🔧 Tier 2 | **`create_pr::tests` temp file collision 修正 (flaky test) — `tempfile` 移行 (PR #224 post-merge-feedback T2-4 採用)** | todo13.md | S | なし (並列 `cargo test` で `body_with_literal_newline_converted` が PID+ms 衝突で稀 fail、pre-existing。target は `cli-pr-monitor/src/stages/create_pr.rs` (report の cli-github は誤り)、CI 信頼性) |
 | 231 | 💎 Tier 3 | **ADR-022 拡張 — pre-create cleanup flow 例 + agent fmt スコープ指針 (PR #224 post-merge-feedback T3-1 採用)** | todo13.md | S | なし (CodeRabbit が `create_fix_commit` の空 findings 設計を bug 誤判定=却下 CR#2、agent 無差別 fmt の 2 事象を ADR-022 責務分離で codify、doc-only) |
 | 232 | 🔧 Tier 2 | **post-merge-feedback / workflow agent の repo 作業ツリー書込禁止 + 検知安全網 (PR #224 セッション合意)** | todo13.md | S-M | なし (merge 時に analyze-session agent が repo root に throwaway script (parse_transcript.py) を残した、日常工程ゆえ累積リスク = コンテキスト汚染。(1) feedback facets に repo 書込禁止 + jq/scratch 使用を明記 (2) post_steps/Stop hook で root 新規 untracked を warning 検知 (3) gitignore は補助) |
 
diff --git a/docs/todo13.md b/docs/todo13.md
index 91bd62dd..12bd05bf 100644
--- a/docs/todo13.md
+++ b/docs/todo13.md
@@ -137,54 +137,6 @@
 
 ---
 
-### 共有 `env_override_lock` helper 抽出 — 並列 test の state file override 競合解消 (PR #224 post-merge-feedback T2-2 採用)
-
-> **動機**: `PR_MONITOR_STATE_FILE_OVERRIDE` (process-global env var) 用の `static LOCK` を複数の test module (poll/mod.rs, rate_limit.rs, review_recheck.rs 等) が独立定義しており、並列 `cargo test` で state file override が競合するリスク。CodeRabbit outside-diff comment でも指摘。
->
-> **本タスクの位置づけ**: PR #224 post-merge-feedback Tier 2 #2 採用 (Effort S / Frequency Medium)。
->
-> **参照**: `.claude/feedback-reports/224.md` Tier 2 #2、各 test module の `env_override_lock()` / `static LOCK`、memory `feedback_test_dry_antipattern` (※下記の境界判断あり)。
->
-> **実行優先度**: 🔧 **Tier 2** — Effort S。
->
-> **重要 (規約整合)**: memory `feedback_test_dry_antipattern` は「test helper は共有 module 抽出せず per-module 複製」を原則とする。一方 env override LOCK は **process-global な serialization 用 static** で、複製すると各々が別 Mutex になり並列競合を防げない (= 複製が機能を壊す特殊ケース)。本タスクは「複製が正しい通常 helper」と「単一 static が必須な lock」を区別し、後者のみ共有化する。着手前にこの境界をユーザー確認。
-
-#### 作業計画
-
-- [ ] env override 用の単一 `static LOCK` を 1 箇所に集約し各 test module から参照
-- [ ] `feedback_test_dry_antipattern` との整合を明文化 (serialization primitive = 単一必須 / 通常 helper = 複製、の区別)
-- [ ] 並列 `cargo test` で state file override 競合が起きないことを確認
-- [ ] 本 entry 削除 + todo-summary.md 行削除
-
-#### 完了基準
-
-- env override の serialization が単一 LOCK で保証され並列 test で競合しない。per-module 複製原則との境界がドキュメント化される。
-
----
-
-### `create_pr::tests` temp file collision 修正 (flaky test) — `tempfile` 移行 (PR #224 post-merge-feedback T2-4 採用)
-
-> **動機**: 並列 `cargo test` で `create_pr::tests::body_with_literal_newline_converted` が稀に fail する (temp file 名が PID+ms timestamp で衝突)。PR-W2 分割以前から存在する pre-existing flaky で、PR #224 セッション中に実観測。flaky の常態化は test 全体の信頼性 (グリーンの価値) を損なう。
->
-> **本タスクの位置づけ**: PR #224 post-merge-feedback Tier 2 #4 採用 + セッション実観測。
->
-> **参照**: `.claude/feedback-reports/224.md` Tier 2 #4、`src/cli-pr-monitor/src/stages/create_pr.rs` `convert_body_to_file` (temp file 名生成。※ report の target `src/cli-github/...` は誤りで、実際は cli-pr-monitor)、`tempfile` crate (既に依存)。
->
-> **実行優先度**: 🔧 **Tier 2** — Effort S。CI 信頼性。
-
-#### 作業計画
-
-- [ ] `convert_body_to_file` の temp file 名生成を PID+ms timestamp から `tempfile::NamedTempFile` (一意保証) に移行
-- [ ] 繰り返し並列実行で衝突しないことを確認
-- [ ] `cargo test -p cli-pr-monitor` pass
-- [ ] 本 entry 削除 + todo-summary.md 行削除
-
-#### 完了基準
-
-- `body_with_literal_newline_converted` 等が並列実行でも安定 pass、temp file 名衝突が構造的に解消。
-
----
-
 ### ADR-022 拡張 — pre-create cleanup flow の具体例 + agent fmt スコープ指針 (PR #224 post-merge-feedback T3-1 採用)
 
 > **動機**: PR #224 で CodeRabbit が `create_fix_commit` の「空 findings でも commit 作成」を bug と誤判定した (ADR-022 の意図的な pre-create 設計を知らなかったため、却下した CR#2)。また分割 agent が無差別 `cargo fmt` を実行した事象も ADR-022 の責務分離原則で説明可能。両事象とも将来再発が見込まれる。
diff --git a/src/cli-pr-monitor/Cargo.toml b/src/cli-pr-monitor/Cargo.toml
index 6ce11f36..762b6f93 100644
--- a/src/cli-pr-monitor/Cargo.toml
+++ b/src/cli-pr-monitor/Cargo.toml
@@ -7,13 +7,15 @@ edition = "2021"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 toml = "0.8"
+# tempfile は本番の convert_body_to_file が --body-file 用一時ファイルを
+# 一意名 (O_EXCL + ランダム名) で生成するために使用 (順位 230 flaky 修正)。
+tempfile = "3"
 lib-jj-helpers = { path = "../lib-jj-helpers" }
 lib-pending-file = { path = "../lib-pending-file" }
 lib-report-formatter = { path = "../lib-report-formatter" }
 lib-subprocess = { path = "../lib-subprocess" }
 
 [dev-dependencies]
-tempfile = "3"
 proptest = "1"
 
 # [profile.release] は workspace root (Cargo.toml) に集約 (ADR-026)
diff --git a/src/cli-pr-monitor/src/stages/create_pr.rs b/src/cli-pr-monitor/src/stages/create_pr.rs
index 4153e480..46f68c97 100644
--- a/src/cli-pr-monitor/src/stages/create_pr.rs
+++ b/src/cli-pr-monitor/src/stages/create_pr.rs
@@ -1,10 +1,12 @@
-use std::path::PathBuf;
+use std::path::Path;
+
+use tempfile::TempPath;
 
 use crate::config::DEFAULT_STEP_TIMEOUT_SECS;
 use crate::log::log_info;
 use crate::runner::{run_cmd_direct, run_gh_quiet};
 use crate::stages::monitor::start_monitoring;
-use crate::state::{write_state, PrMonitorState};
+use crate::state::{state_file_path, write_state_to, PrMonitorState};
 use crate::util::{
     get_jj_bookmarks, get_pr_head_commit, get_pr_info, parse_pr_number_from_url, utc_now_iso8601,
     PrInfo,
@@ -43,46 +45,45 @@ fn reassemble_split_body(args: &[String]) -> Vec<String> {
     result
 }
 
-// ─── --body -> --body-file 変換 (issue #1) ───
-
-/// Drop 時に自動削除される一時ファイル
-struct TempFile(PathBuf);
-
-impl Drop for TempFile {
-    fn drop(&mut self) {
-        let _ = std::fs::remove_file(&self.0);
-    }
+/// `dir` 配下に一意な一時ファイルを作成し `content` を書き出す。
+///
+/// 返り値の `TempPath` は Drop 時に自動削除される (旧 `TempFile` struct の役割)。
+/// `tempfile` は `O_EXCL` + ランダム名 + 衝突時リトライでファイルを作るため、
+/// 並列 `cargo test` (同一プロセス・同一 ms) でも本番の並列実行 (別セッション /
+/// サブエージェント) でも名前が構造的に衝突しない (順位 230 flaky 修正)。
+fn write_body_tempfile(dir: &Path, content: &str) -> std::io::Result<TempPath> {
+    let path = tempfile::Builder::new()
+        .prefix("gh-pr-body-")
+        .suffix(".md")
+        .tempfile_in(dir)?
+        .into_temp_path();
+    std::fs::write(&path, content)?;
+    Ok(path)
 }
 
 /// --body 引数に改行が含まれる場合、一時ファイルに書き出して --body-file に差し替える。
-fn convert_body_to_file(args: &[String]) -> (Vec<String>, Option<TempFile>) {
+///
+/// `temp_dir` は生成先ディレクトリ。本番は `std::env::temp_dir()` を渡し、テストは
+/// 各 test 専用の `tempfile::tempdir()` を注入して本番 namespace から分離する。
+fn convert_body_to_file(args: &[String], temp_dir: &Path) -> (Vec<String>, Option<TempPath>) {
     let mut result = Vec::with_capacity(args.len());
     let mut i = 0;
-    let mut temp_guard: Option<TempFile> = None;
+    let mut temp_guard: Option<TempPath> = None;
 
     while i < args.len() {
         if args[i] == "--body" && i + 1 < args.len() {
             let body = &args[i + 1];
             if body.contains('\n') || body.contains("\\n") {
-                let filename = format!(
-                    "gh-pr-body-{}-{}.md",
-                    std::process::id(),
-                    std::time::SystemTime::now()
-                        .duration_since(std::time::UNIX_EPOCH)
-                        .unwrap_or_default()
-                        .as_millis()
-                );
-                let path = std::env::temp_dir().join(filename);
                 let resolved = body.replace("\\n", "\n");
-                match std::fs::write(&path, &resolved) {
-                    Ok(()) => {
+                match write_body_tempfile(temp_dir, &resolved) {
+                    Ok(path) => {
                         log_info(&format!(
                             "--body に改行を検出 → --body-file に変換 ({})",
                             path.display()
                         ));
                         result.push("--body-file".to_string());
                         result.push(path.to_string_lossy().to_string());
-                        temp_guard = Some(TempFile(path));
+                        temp_guard = Some(path);
                     }
                     Err(e) => {
                         log_info(&format!(
@@ -203,14 +204,14 @@ pub(crate) fn run_create_pr(gh_args: &[String]) -> i32 {
 
 fn write_early_reset_state() {
     let early_state = PrMonitorState::new(None, None, utc_now_iso8601());
-    if let Err(e) = write_state(&early_state) {
+    if let Err(e) = write_state_to(&state_file_path(), &early_state) {
         log_info(&format!("[state] 早期 reset 書き込み失敗 (継続): {}", e));
     }
 }
 
-fn prepare_gh_pr_create_args(gh_args: &[String]) -> (Vec<String>, Option<TempFile>) {
+fn prepare_gh_pr_create_args(gh_args: &[String]) -> (Vec<String>, Option<TempPath>) {
     let reassembled = reassemble_split_body(gh_args);
-    let (mut final_args, body_tempfile) = convert_body_to_file(&reassembled);
+    let (mut final_args, body_tempfile) = convert_body_to_file(&reassembled, &std::env::temp_dir());
 
     if !has_head_flag(&final_args) {
         let bookmarks = get_jj_bookmarks();
@@ -380,46 +381,50 @@ mod tests {
 
     #[test]
     fn body_without_newline_unchanged() {
+        let dir = tempfile::tempdir().unwrap();
         let args = vec![
             "--title".into(),
             "test".into(),
             "--body".into(),
             "simple body".into(),
         ];
-        let (result, temp) = convert_body_to_file(&args);
+        let (result, temp) = convert_body_to_file(&args, dir.path());
         assert_eq!(result, args);
         assert!(temp.is_none());
     }
 
     #[test]
     fn body_with_literal_newline_converted() {
+        let dir = tempfile::tempdir().unwrap();
         let args = vec![
             "--title".into(),
             "test".into(),
             "--body".into(),
             "line1\\nline2".into(),
         ];
-        let (result, temp) = convert_body_to_file(&args);
+        let (result, temp) = convert_body_to_file(&args, dir.path());
         assert_eq!(result[0], "--title");
         assert_eq!(result[1], "test");
         assert_eq!(result[2], "--body-file");
         assert!(temp.is_some());
-        let content = std::fs::read_to_string(&temp.as_ref().unwrap().0).unwrap();
+        let content = std::fs::read_to_string(temp.as_ref().unwrap()).unwrap();
         assert!(content.contains("line1\nline2"));
     }
 
     #[test]
     fn body_with_real_newline_converted() {
+        let dir = tempfile::tempdir().unwrap();
         let args = vec!["--body".into(), "line1\nline2".into()];
-        let (result, temp) = convert_body_to_file(&args);
+        let (result, temp) = convert_body_to_file(&args, dir.path());
         assert_eq!(result[0], "--body-file");
         assert!(temp.is_some());
     }
 
     #[test]
     fn no_body_arg_unchanged() {
+        let dir = tempfile::tempdir().unwrap();
         let args = vec!["--title".into(), "test".into()];
-        let (result, temp) = convert_body_to_file(&args);
+        let (result, temp) = convert_body_to_file(&args, dir.path());
         assert_eq!(result, args);
         assert!(temp.is_none());
     }
diff --git a/src/cli-pr-monitor/src/stages/monitor.rs b/src/cli-pr-monitor/src/stages/monitor.rs
index 2fbe5afc..aabe6840 100644
--- a/src/cli-pr-monitor/src/stages/monitor.rs
+++ b/src/cli-pr-monitor/src/stages/monitor.rs
@@ -1,3 +1,5 @@
+use std::path::Path;
+
 use crate::config::load_config;
 use crate::fix_commit::{create_fix_commit, FixCommitState};
 use crate::lock::{acquire as acquire_lock, LockResult};
@@ -6,7 +8,7 @@ use crate::stages::collect::collect_findings;
 use crate::stages::poll::run_poll_loop;
 use crate::stages::repush::execute_repush_flow;
 use crate::stages::takt::run_takt;
-use crate::state::{read_state, write_state, PrMonitorState};
+use crate::state::{read_state_from, state_file_path, write_state_to, PrMonitorState};
 use crate::util::{get_pr_info, utc_now_iso8601, PrInfo};
 
 // ─── 監視開始 (sequential chain) ───
@@ -95,7 +97,7 @@ fn init_or_resume_state(pr_info: &PrInfo, is_wakeup: bool, pr_label: &str) {
         pr_info.push_time.clone().unwrap_or_else(utc_now_iso8601),
     );
     init_state.fix_push_time = pr_info.fix_push_time.clone();
-    if let Err(e) = write_state(&init_state) {
+    if let Err(e) = write_state_to(&state_file_path(), &init_state) {
         log_info(&format!("[state] 初期化書き込み失敗 (継続): {}", e));
     }
 }
@@ -206,7 +208,8 @@ pub(crate) fn run_monitor_only() -> i32 {
             resume_push_time
         ));
         pr_info.push_time = Some(resume_push_time.clone());
-        pr_info.fix_push_time = resume_fix_push_time_or_started_at(&resume_push_time);
+        pr_info.fix_push_time =
+            resume_fix_push_time_or_started_at(&resume_push_time, &state_file_path());
         start_monitoring_wakeup(&pr_info)
     } else {
         let now = utc_now_iso8601();
@@ -218,8 +221,11 @@ pub(crate) fn run_monitor_only() -> i32 {
 
 /// 順位 141: wakeup resume 経路で state から `fix_push_time` を取り出す。
 /// legacy state (本フィールド未設定) では `started_at` に fallback して挙動を維持する。
-fn resume_fix_push_time_or_started_at(started_at_fallback: &str) -> Option<String> {
-    read_state()
+fn resume_fix_push_time_or_started_at(
+    started_at_fallback: &str,
+    state_path: &Path,
+) -> Option<String> {
+    read_state_from(state_path)
         .and_then(|s| s.fix_push_time)
         .or_else(|| Some(started_at_fallback.to_string()))
 }
@@ -230,7 +236,7 @@ fn resume_fix_push_time_or_started_at(started_at_fallback: &str) -> Option<Strin
 /// CR Major #1 fix (Bb-2 PR #114 review): 同一 PR でも新 commit が push されれば head_commit
 /// が変わるため、stored vs current head 一致も check する。head 不一致なら fresh push 扱い。
 fn detect_wakeup_resume(pr_info: &PrInfo) -> Option<String> {
-    let state = read_state()?;
+    let state = read_state_from(&state_file_path())?;
     let now_unix = std::time::SystemTime::now()
         .duration_since(std::time::UNIX_EPOCH)
         .map(|d| d.as_secs() as i64)
@@ -581,27 +587,16 @@ mod tests {
         assert_eq!(compute_verdict(&r), VERDICT_NO_PROBLEMS);
     }
 
-    /// PR_MONITOR_STATE_FILE_OVERRIDE は process-global env var のため、
-    /// override 設定 / 解除を test 並行実行で race させない serial guard。
-    fn env_override_lock() -> std::sync::MutexGuard<'static, ()> {
-        use std::sync::{Mutex, OnceLock};
-        static LOCK: OnceLock<Mutex<()>> = OnceLock::new();
-        LOCK.get_or_init(|| Mutex::new(())).lock().unwrap()
-    }
-
     /// 順位 141: `resume_fix_push_time_or_started_at` Case A —
     /// state に `fix_push_time` が設定済みの場合、fallback の `started_at` ではなく
     /// state の値が返されることを検証する。
     #[test]
     fn resume_returns_fix_push_time_from_state_when_set() {
-        let _guard = env_override_lock();
         let tmp = tempfile::NamedTempFile::new().unwrap();
         let mut s = PrMonitorState::new(Some(1), None, "t".into());
         s.fix_push_time = Some("2026-05-22T06:06:00Z".into());
         std::fs::write(tmp.path(), serde_json::to_string(&s).unwrap()).unwrap();
-        std::env::set_var("PR_MONITOR_STATE_FILE_OVERRIDE", tmp.path());
-        let result = resume_fix_push_time_or_started_at("2026-05-22T06:00:00Z");
-        std::env::remove_var("PR_MONITOR_STATE_FILE_OVERRIDE");
+        let result = resume_fix_push_time_or_started_at("2026-05-22T06:00:00Z", tmp.path());
         assert_eq!(
             result.as_deref(),
             Some("2026-05-22T06:06:00Z"),
diff --git a/src/cli-pr-monitor/src/stages/poll/iteration.rs b/src/cli-pr-monitor/src/stages/poll/iteration.rs
index 99b82b51..bc4f6d06 100644
--- a/src/cli-pr-monitor/src/stages/poll/iteration.rs
+++ b/src/cli-pr-monitor/src/stages/poll/iteration.rs
@@ -1,3 +1,4 @@
+use std::path::Path;
 use std::time::Duration;
 
 use crate::classifier_runner::classify_findings;
@@ -5,7 +6,7 @@ use crate::config::{ClassifierConfig, DEFAULT_CHECK_TIMEOUT_SECS};
 use crate::log::{log_info, truncate_safe};
 use crate::runner::run_cmd_direct;
 use crate::state::{
-    read_state, update_state_from_check_result, write_state, CiState, CodeRabbitState,
+    read_state_from, update_state_from_check_result, write_state_to, CiState, CodeRabbitState,
     PrMonitorState,
 };
 use crate::util::{utc_now_iso8601, PrInfo};
@@ -26,8 +27,9 @@ pub(super) fn run_one_iteration(ctx: &PollContext<'_>) -> Option<PollResult> {
         &result,
         ctx.skip_ci,
         ctx.skip_coderabbit,
+        ctx.state_path,
     );
-    enrich_with_classifier(&mut state, ctx.classifier_config);
+    enrich_with_classifier(&mut state, ctx.classifier_config, ctx.state_path);
     log_info(&format!(
         "ポーリング: action={}, summary={}",
         state.action, state.summary
@@ -43,6 +45,7 @@ pub(super) fn run_one_iteration(ctx: &PollContext<'_>) -> Option<PollResult> {
         ctx.pr_info,
         ctx.review_recheck_wait_secs,
         &result,
+        ctx.state_path,
     ) {
         return Some(terminal);
     }
@@ -104,6 +107,7 @@ fn build_state_for_iteration(
     result: &serde_json::Value,
     skip_ci: bool,
     skip_coderabbit: bool,
+    state_path: &Path,
 ) -> PrMonitorState {
     let mut state = PrMonitorState::new(
         pr_info.pr_number,
@@ -112,7 +116,7 @@ fn build_state_for_iteration(
     );
     update_state_from_check_result(&mut state, result);
 
-    if let Some(existing) = read_state() {
+    if let Some(existing) = read_state_from(state_path) {
         state.notified = existing.notified;
         state.rate_limit_retries = existing.rate_limit_retries;
         state.rate_limit_last_retriggered_at = existing.rate_limit_last_retriggered_at;
@@ -124,7 +128,7 @@ fn build_state_for_iteration(
 
     apply_skip_handling(&mut state, skip_ci, skip_coderabbit);
     state.last_checked = Some(utc_now_iso8601());
-    if let Err(e) = write_state(&state) {
+    if let Err(e) = write_state_to(state_path, &state) {
         log_info(&format!("state 書き込み失敗 (skip 反映後、続行): {}", e));
     }
     state
@@ -135,7 +139,11 @@ fn build_state_for_iteration(
 /// `config.classifier.enabled = false` または findings が空のときは何もしない。
 /// 実行成功時は state.classified_findings を populate して state file を再書き出す。
 /// 失敗時は state.classified_findings は空のまま (caller は findings をそのまま使えばよい)。
-fn enrich_with_classifier(state: &mut PrMonitorState, config: &ClassifierConfig) {
+fn enrich_with_classifier(
+    state: &mut PrMonitorState,
+    config: &ClassifierConfig,
+    state_path: &Path,
+) {
     if !config.enabled || state.findings.is_empty() {
         return;
     }
@@ -148,7 +156,7 @@ fn enrich_with_classifier(state: &mut PrMonitorState, config: &ClassifierConfig)
         classified.len()
     ));
     state.classified_findings = classified;
-    if let Err(e) = write_state(state) {
+    if let Err(e) = write_state_to(state_path, state) {
         log_info(&format!(
             "state 書き込み失敗 (classifier enrich 後、続行): {}",
             e
@@ -312,8 +320,9 @@ mod tests {
             enabled: false,
             ..ClassifierConfig::default()
         };
+        let dir = tempfile::tempdir().unwrap();
 
-        enrich_with_classifier(&mut state, &disabled);
+        enrich_with_classifier(&mut state, &disabled, &dir.path().join("state.json"));
 
         assert_eq!(
             state.classified_findings,
@@ -353,8 +362,9 @@ mod tests {
             enabled: true,
             ..ClassifierConfig::default()
         };
+        let dir = tempfile::tempdir().unwrap();
 
-        enrich_with_classifier(&mut state, &enabled);
+        enrich_with_classifier(&mut state, &enabled, &dir.path().join("state.json"));
 
         assert_eq!(
             state.classified_findings,
diff --git a/src/cli-pr-monitor/src/stages/poll/mod.rs b/src/cli-pr-monitor/src/stages/poll/mod.rs
index b6478dca..d69dfc07 100644
--- a/src/cli-pr-monitor/src/stages/poll/mod.rs
+++ b/src/cli-pr-monitor/src/stages/poll/mod.rs
@@ -30,6 +30,8 @@ pub(crate) struct PollResult {
 
 pub(super) struct PollContext<'a> {
     pub(super) checker: &'a std::path::Path,
+    /// state file の保存先 (順位 229: テストは自前 path を注入し env var 競合を排除)。
+    pub(super) state_path: &'a std::path::Path,
     pub(super) push_time: &'a str,
     /// 順位 141: fresh push 時刻の固定値 (CR rate-limit detection bug 修正)。
     /// 設定されていれば `build_checker_args` で `--push-time` に優先採用される。
@@ -70,8 +72,10 @@ pub(crate) fn run_poll_loop(full_config: &Config, pr_info: &PrInfo, is_wakeup: b
         return error_poll_result("check-ci-coderabbit.exe が見つかりません");
     }
 
+    let state_path = crate::state::state_file_path();
     let ctx = PollContext {
         checker: &checker,
+        state_path: &state_path,
         push_time: pr_info
             .push_time
             .as_deref()
@@ -131,15 +135,7 @@ mod tests {
     use rate_limit::finalize_parked;
     use review_recheck::{finalize_initial_review_park, schedule_next_review_recheck_park};
 
-    /// PR_MONITOR_STATE_FILE_OVERRIDE は process-global env var のため、
-    /// override 設定 / 解除を test 並行実行で race させない serial guard。
-    fn env_override_lock() -> std::sync::MutexGuard<'static, ()> {
-        use std::sync::{Mutex, OnceLock};
-        static LOCK: OnceLock<Mutex<()>> = OnceLock::new();
-        LOCK.get_or_init(|| Mutex::new(())).lock().unwrap()
-    }
-
-    /// 書き込み先がディレクトリ不在のため write が必ず失敗する override path を返す。
+    /// 書き込み先がディレクトリ不在のため write が必ず失敗する path を返す。
     fn unwritable_state_path() -> std::path::PathBuf {
         std::env::temp_dir()
             .join(format!("pr-monitor-T2-2-{}", std::process::id()))
@@ -147,7 +143,10 @@ mod tests {
             .join("state.json")
     }
 
-    fn invoke_finalize_parked_with_bad_path(pr_info: &crate::util::PrInfo) -> PollResult {
+    fn invoke_finalize_parked_with_bad_path(
+        pr_info: &crate::util::PrInfo,
+        state_path: &std::path::Path,
+    ) -> PollResult {
         let mut state = PrMonitorState::new(Some(1), Some("o/r".into()), "t".into());
         let rl = RateLimitState {
             until_unix_secs: 1_775_088_000,
@@ -156,10 +155,21 @@ mod tests {
             wait_seconds: 0,
         };
         let result = serde_json::json!({});
-        finalize_parked(&mut state, &rl, pr_info, 1_775_088_000, 3, &result)
+        finalize_parked(
+            &mut state,
+            &rl,
+            pr_info,
+            1_775_088_000,
+            3,
+            &result,
+            state_path,
+        )
     }
 
-    fn invoke_review_park_with_bad_path(pr_info: &crate::util::PrInfo) -> PollResult {
+    fn invoke_review_park_with_bad_path(
+        pr_info: &crate::util::PrInfo,
+        state_path: &std::path::Path,
+    ) -> PollResult {
         let mut state =
             PrMonitorState::new(Some(1), Some("o/r".into()), "2026-05-01T00:00:00Z".into());
         state.review_recheck_count = 1;
@@ -168,6 +178,7 @@ mod tests {
         let classifier_config = ClassifierConfig::default();
         let ctx = PollContext {
             checker: &checker_path,
+            state_path,
             push_time: "2026-05-01T00:00:00Z",
             fix_push_time: None,
             pr_info,
@@ -186,12 +197,14 @@ mod tests {
 
     fn invoke_finalize_initial_review_park_with_bad_path(
         pr_info: &crate::util::PrInfo,
+        state_path: &std::path::Path,
     ) -> PollResult {
         let checker_path = std::path::PathBuf::from("dummy");
         let rate_limit_config = RateLimitConfig::default();
         let classifier_config = ClassifierConfig::default();
         let ctx = PollContext {
             checker: &checker_path,
+            state_path,
             push_time: "2026-05-01T00:00:00Z",
             fix_push_time: None,
             pr_info,
@@ -215,9 +228,7 @@ mod tests {
     /// invariant 維持を強制する。
     #[test]
     fn finalize_park_siblings_have_symmetric_write_state_handling() {
-        let _guard = env_override_lock();
         let bad_path = unwritable_state_path();
-        std::env::set_var("PR_MONITOR_STATE_FILE_OVERRIDE", &bad_path);
 
         let pr_info = crate::util::PrInfo {
             pr_number: Some(1),
@@ -227,11 +238,10 @@ mod tests {
             fix_push_time: None,
         };
 
-        let outcome_rate_limit = invoke_finalize_parked_with_bad_path(&pr_info);
-        let outcome_review = invoke_review_park_with_bad_path(&pr_info);
-        let outcome_initial = invoke_finalize_initial_review_park_with_bad_path(&pr_info);
-
-        std::env::remove_var("PR_MONITOR_STATE_FILE_OVERRIDE");
+        let outcome_rate_limit = invoke_finalize_parked_with_bad_path(&pr_info, &bad_path);
+        let outcome_review = invoke_review_park_with_bad_path(&pr_info, &bad_path);
+        let outcome_initial =
+            invoke_finalize_initial_review_park_with_bad_path(&pr_info, &bad_path);
 
         assert_eq!(
             outcome_rate_limit.action, "action_required",
diff --git a/src/cli-pr-monitor/src/stages/poll/rate_limit.rs b/src/cli-pr-monitor/src/stages/poll/rate_limit.rs
index cde81aeb..2653ade4 100644
--- a/src/cli-pr-monitor/src/stages/poll/rate_limit.rs
+++ b/src/cli-pr-monitor/src/stages/poll/rate_limit.rs
@@ -10,10 +10,12 @@
 //! signal 整形部分 (`format_park_signal` / shortcut signal /
 //! `format_posted_retrigger_review_park_signal`) は `rate_limit_signal.rs` に分離。
 
+use std::path::Path;
+
 use crate::config::RateLimitConfig;
 use crate::log::log_info;
 use crate::runner::run_gh_quiet;
-use crate::state::{write_state, PrMonitorState};
+use crate::state::{write_state_to, PrMonitorState};
 use crate::util::PrInfo;
 
 use super::rate_limit_signal::{
@@ -33,6 +35,7 @@ pub(super) fn handle_rate_limit_branch(
     pr_info: &PrInfo,
     review_recheck_wait_secs: u64,
     result: &serde_json::Value,
+    state_path: &Path,
 ) -> Option<PollResult> {
     let rl = state.rate_limit.clone()?;
     let already_handled =
@@ -65,6 +68,7 @@ pub(super) fn handle_rate_limit_branch(
         rate_limit_config.max_retries,
         review_recheck_wait_secs,
         result,
+        state_path,
     )
 }
 
@@ -75,11 +79,17 @@ fn dispatch_rate_limit_outcome(
     max_retries: u32,
     review_recheck_wait_secs: u64,
     result: &serde_json::Value,
+    state_path: &Path,
 ) -> Option<PollResult> {
     match handle_rate_limit_retry(rl, state, pr_info, max_retries) {
-        RateLimitOutcome::Posted => {
-            finalize_posted_retrigger(state, rl, pr_info, review_recheck_wait_secs, result)
-        }
+        RateLimitOutcome::Posted => finalize_posted_retrigger(
+            state,
+            rl,
+            pr_info,
+            review_recheck_wait_secs,
+            result,
+            state_path,
+        ),
         RateLimitOutcome::Parked { wakeup_at_unix } => Some(finalize_parked(
             state,
             rl,
@@ -87,6 +97,7 @@ fn dispatch_rate_limit_outcome(
             wakeup_at_unix,
             max_retries,
             result,
+            state_path,
         )),
         RateLimitOutcome::Failed(e) => {
             log_info(&format!("[rate_limit] retrigger 失敗: {}", e));
@@ -108,6 +119,7 @@ pub(super) fn finalize_posted_retrigger(
     pr_info: &PrInfo,
     review_recheck_wait_secs: u64,
     result: &serde_json::Value,
+    state_path: &Path,
 ) -> Option<PollResult> {
     state.rate_limit_last_retriggered_at = Some(rl.comment_event_time.clone());
 
@@ -126,7 +138,7 @@ pub(super) fn finalize_posted_retrigger(
         review_recheck_wait_secs
     );
 
-    if let Err(e) = write_state(state) {
+    if let Err(e) = write_state_to(state_path, state) {
         log_info(&format!(
             "[rate_limit] retrigger 後の state 永続化失敗、自動 retry を停止: {}",
             e
@@ -154,6 +166,7 @@ pub(super) fn finalize_parked(
     wakeup_at_unix: i64,
     max_retries: u32,
     result: &serde_json::Value,
+    state_path: &Path,
 ) -> PollResult {
     state.action = "parked_rate_limit".into();
     state.next_wakeup_at_unix = Some(wakeup_at_unix);
@@ -163,7 +176,7 @@ pub(super) fn finalize_parked(
         "CodeRabbit rate-limit: wakeup を {}m{}s 後に予約 (PARK signal 参照)",
         rl.wait_minutes, rl.wait_seconds
     );
-    if let Err(e) = write_state(state) {
+    if let Err(e) = write_state_to(state_path, state) {
         let msg = format!("park state 永続化失敗のため PARK signal を中止 ({})。手動で `@coderabbitai review` を投稿してください", e);
         return make_action_required_result(state, result, &msg);
     }
@@ -441,15 +454,7 @@ mod tests {
         assert!(state.rate_limit_last_retriggered_at.is_none());
     }
 
-    /// PR_MONITOR_STATE_FILE_OVERRIDE は process-global env var のため、
-    /// override 設定 / 解除を test 並行実行で race させない serial guard。
-    fn env_override_lock() -> std::sync::MutexGuard<'static, ()> {
-        use std::sync::{Mutex, OnceLock};
-        static LOCK: OnceLock<Mutex<()>> = OnceLock::new();
-        LOCK.get_or_init(|| Mutex::new(())).lock().unwrap()
-    }
-
-    /// 書き込み先がディレクトリ不在のため write が必ず失敗する override path を返す。
+    /// 書き込み先がディレクトリ不在のため write が必ず失敗する path を返す。
     fn unwritable_state_path() -> std::path::PathBuf {
         std::env::temp_dir()
             .join(format!("pr-monitor-T2-2-{}", std::process::id()))
@@ -461,9 +466,7 @@ mod tests {
     /// `action_required` を返却する fail-safe 経路を持つ (CodeRabbit Major #1 fix の固定化)。
     #[test]
     fn finalize_parked_returns_action_required_when_write_state_fails() {
-        let _guard = env_override_lock();
         let bad_path = unwritable_state_path();
-        std::env::set_var("PR_MONITOR_STATE_FILE_OVERRIDE", &bad_path);
 
         let mut state = PrMonitorState::new(Some(42), Some("o/r".into()), "t".into());
         let rl = RateLimitState {
@@ -481,9 +484,15 @@ mod tests {
         };
         let result = serde_json::json!({});
 
-        let outcome = finalize_parked(&mut state, &rl, &pr_info, 1_775_088_000, 3, &result);
-
-        std::env::remove_var("PR_MONITOR_STATE_FILE_OVERRIDE");
+        let outcome = finalize_parked(
+            &mut state,
+            &rl,
+            &pr_info,
+            1_775_088_000,
+            3,
+            &result,
+            &bad_path,
+        );
 
         assert_eq!(
             outcome.action, "action_required",
@@ -519,16 +528,18 @@ mod tests {
 
     #[test]
     fn finalize_posted_retrigger_schedules_park_after_post() {
-        let _guard = env_override_lock();
         let tmp = tempfile::tempdir().unwrap();
         let state_path = tmp.path().join("state.json");
-        std::env::set_var("PR_MONITOR_STATE_FILE_OVERRIDE", &state_path);
 
         let (mut state, rl, pr_info) = setup_posted_retrigger_fixture();
-        let result =
-            finalize_posted_retrigger(&mut state, &rl, &pr_info, 300, &serde_json::Value::Null);
-
-        std::env::remove_var("PR_MONITOR_STATE_FILE_OVERRIDE");
+        let result = finalize_posted_retrigger(
+            &mut state,
+            &rl,
+            &pr_info,
+            300,
+            &serde_json::Value::Null,
+            &state_path,
+        );
 
         let park_result =
             result.expect("順位 80 fix: Posted 後は必ず park を返し silent exit を防ぐ");
@@ -553,9 +564,7 @@ mod tests {
 
     #[test]
     fn finalize_posted_retrigger_action_required_when_write_state_fails() {
-        let _guard = env_override_lock();
         let bad_path = unwritable_state_path();
-        std::env::set_var("PR_MONITOR_STATE_FILE_OVERRIDE", &bad_path);
 
         let mut state = PrMonitorState::new(Some(1), Some("o/r".into()), "t".into());
         state.action = "continue_monitoring".into();
@@ -573,10 +582,14 @@ mod tests {
             fix_push_time: None,
         };
 
-        let result =
-            finalize_posted_retrigger(&mut state, &rl, &pr_info, 300, &serde_json::Value::Null);
-
-        std::env::remove_var("PR_MONITOR_STATE_FILE_OVERRIDE");
+        let result = finalize_posted_retrigger(
+            &mut state,
+            &rl,
+            &pr_info,
+            300,
+            &serde_json::Value::Null,
+            &bad_path,
+        );
 
         assert!(result.is_some());
         assert_eq!(
diff --git a/src/cli-pr-monitor/src/stages/poll/review_recheck.rs b/src/cli-pr-monitor/src/stages/poll/review_recheck.rs
index a79c6710..727fa43d 100644
--- a/src/cli-pr-monitor/src/stages/poll/review_recheck.rs
+++ b/src/cli-pr-monitor/src/stages/poll/review_recheck.rs
@@ -7,8 +7,10 @@
 //! signal 整形部分 (`round_up_to_next_minute` / `compute_safe_minute_for_park_signal` /
 //! `format_review_park_signal`) は `review_recheck_signal.rs` に分離。
 
+use std::path::Path;
+
 use crate::log::log_info;
-use crate::state::{read_state, write_state, PrMonitorState};
+use crate::state::{read_state_from, write_state_to, PrMonitorState};
 
 use super::rate_limit::make_action_required_result;
 use super::review_recheck_signal::format_review_park_signal;
@@ -25,7 +27,7 @@ use super::{make_park_poll_result, PollContext, PollResult};
 /// 食い違い、最悪 max 到達状態で park される)。
 /// CR Major #1 fix: head_commit を state に保存し detect_wakeup_resume の比較対象とする。
 pub(super) fn finalize_initial_review_park(ctx: &PollContext<'_>) -> PollResult {
-    let mut state = read_state().unwrap_or_else(|| {
+    let mut state = read_state_from(ctx.state_path).unwrap_or_else(|| {
         PrMonitorState::new(
             ctx.pr_info.pr_number,
             ctx.pr_info.repo.clone(),
@@ -52,7 +54,7 @@ pub(super) fn finalize_initial_review_park(ctx: &PollContext<'_>) -> PollResult
         ctx.initial_review_wait_secs, ctx.max_review_rechecks
     );
 
-    if let Err(e) = write_state(&state) {
+    if let Err(e) = write_state_to(ctx.state_path, &state) {
         log_info(&format!(
             "[review_recheck] initial park state 永続化失敗、action_required で抜ける: {}",
             e
@@ -74,7 +76,7 @@ pub(super) fn finalize_initial_review_park(ctx: &PollContext<'_>) -> PollResult
 /// `action_required` で抜ける (review が想定時間内に未完了を通知)。
 /// 未到達なら `review_recheck_wait_secs` 後の wakeup を予約して return。
 pub(super) fn finalize_review_recheck_park(ctx: &PollContext<'_>) -> PollResult {
-    let mut state = read_state().unwrap_or_else(|| {
+    let mut state = read_state_from(ctx.state_path).unwrap_or_else(|| {
         PrMonitorState::new(
             ctx.pr_info.pr_number,
             ctx.pr_info.repo.clone(),
@@ -87,7 +89,11 @@ pub(super) fn finalize_review_recheck_park(ctx: &PollContext<'_>) -> PollResult
         .or_else(|| ctx.fix_push_time.map(String::from));
 
     if state.review_recheck_count >= ctx.max_review_rechecks {
-        return finalize_review_recheck_max_reached(&mut state, ctx.max_review_rechecks);
+        return finalize_review_recheck_max_reached(
+            &mut state,
+            ctx.state_path,
+            ctx.max_review_rechecks,
+        );
     }
 
     schedule_next_review_recheck_park(&mut state, ctx)
@@ -95,6 +101,7 @@ pub(super) fn finalize_review_recheck_park(ctx: &PollContext<'_>) -> PollResult
 
 fn finalize_review_recheck_max_reached(
     state: &mut PrMonitorState,
+    state_path: &Path,
     max_review_rechecks: u32,
 ) -> PollResult {
     log_info(&format!(
@@ -109,7 +116,7 @@ fn finalize_review_recheck_max_reached(
     state.summary = summary.clone();
     state.next_wakeup_at_unix = None;
     state.wakeup_reason = None;
-    if let Err(e) = write_state(state) {
+    if let Err(e) = write_state_to(state_path, state) {
         log_info(&format!(
             "state 書き込み失敗 (action_required 確定後、続行): {}",
             e
@@ -135,7 +142,7 @@ pub(super) fn schedule_next_review_recheck_park(
         ctx.review_recheck_wait_secs, state.review_recheck_count, ctx.max_review_rechecks
     );
 
-    if let Err(e) = write_state(state) {
+    if let Err(e) = write_state_to(ctx.state_path, state) {
         log_info(&format!(
             "[review_recheck] park state 永続化失敗、action_required で抜ける: {}",
             e
@@ -155,23 +162,8 @@ pub(super) fn schedule_next_review_recheck_park(
 mod tests {
     use super::*;
     use crate::config::{ClassifierConfig, RateLimitConfig};
-    use std::sync::{Mutex, OnceLock};
-
-    fn env_lock() -> std::sync::MutexGuard<'static, ()> {
-        static LOCK: OnceLock<Mutex<()>> = OnceLock::new();
-        LOCK.get_or_init(|| Mutex::new(()))
-            .lock()
-            .unwrap_or_else(|e| e.into_inner())
-    }
 
-    /// PR_MONITOR_STATE_FILE_OVERRIDE は process-global env var のため、
-    /// override 設定 / 解除を test 並行実行で race させない serial guard。
-    fn env_override_lock() -> std::sync::MutexGuard<'static, ()> {
-        static LOCK: OnceLock<Mutex<()>> = OnceLock::new();
-        LOCK.get_or_init(|| Mutex::new(())).lock().unwrap()
-    }
-
-    /// 書き込み先がディレクトリ不在のため write が必ず失敗する override path を返す。
+    /// 書き込み先がディレクトリ不在のため write が必ず失敗する path を返す。
     fn unwritable_state_path() -> std::path::PathBuf {
         std::env::temp_dir()
             .join(format!("pr-monitor-T2-2-{}", std::process::id()))
@@ -199,12 +191,14 @@ mod tests {
 
     fn make_default_test_ctx<'a>(
         checker: &'a std::path::Path,
+        state_path: &'a std::path::Path,
         pr_info: &'a crate::util::PrInfo,
         rate_limit_config: &'a RateLimitConfig,
         classifier_config: &'a ClassifierConfig,
     ) -> PollContext<'a> {
         PollContext {
             checker,
+            state_path,
             push_time: "2026-05-01T00:00:00Z",
             fix_push_time: None,
             pr_info,
@@ -225,10 +219,8 @@ mod tests {
     /// "wakeup は parked_* action のときのみスケジュールされる"。
     #[test]
     fn finalize_review_recheck_max_reached_clears_wakeup_fields() {
-        let _guard = env_lock();
         let tmp = tempfile::tempdir().unwrap();
         let state_path = tmp.path().join("state.json");
-        std::env::set_var("PR_MONITOR_STATE_FILE_OVERRIDE", &state_path);
 
         let mut state = PrMonitorState::new(Some(42), Some("o/r".into()), "t".into());
         let stale_wakeup_unix: i64 = 9_999_999_999;
@@ -238,9 +230,7 @@ mod tests {
         state.review_recheck_count = 3;
         state.action = "parked_review_recheck".into();
 
-        finalize_review_recheck_max_reached(&mut state, 3);
-
-        std::env::remove_var("PR_MONITOR_STATE_FILE_OVERRIDE");
+        finalize_review_recheck_max_reached(&mut state, &state_path, 3);
 
         assert!(
             state.next_wakeup_at_unix.is_none(),
@@ -262,9 +252,7 @@ mod tests {
     /// PARK signal emit を中止し `action_required` を返却する (sibling parity)。
     #[test]
     fn schedule_next_review_recheck_park_returns_action_required_when_write_state_fails() {
-        let _guard = env_override_lock();
         let bad_path = unwritable_state_path();
-        std::env::set_var("PR_MONITOR_STATE_FILE_OVERRIDE", &bad_path);
 
         let mut state =
             PrMonitorState::new(Some(42), Some("o/r".into()), "2026-05-01T00:00:00Z".into());
@@ -281,6 +269,7 @@ mod tests {
         let classifier_config = ClassifierConfig::default();
         let ctx = PollContext {
             checker: &checker_path,
+            state_path: &bad_path,
             push_time: "2026-05-01T00:00:00Z",
             fix_push_time: None,
             pr_info: &pr_info,
@@ -297,8 +286,6 @@ mod tests {
 
         let outcome = schedule_next_review_recheck_park(&mut state, &ctx);
 
-        std::env::remove_var("PR_MONITOR_STATE_FILE_OVERRIDE");
-
         assert_eq!(
             outcome.action, "action_required",
             "T2-2 sibling parity: review park も write_state 失敗 → action_required で抜けること"
@@ -310,25 +297,24 @@ mod tests {
     /// で残った state を持ち越さないことを machine-enforce する。
     #[test]
     fn finalize_initial_review_park_resets_recheck_count() {
-        let _guard = env_override_lock();
-        let tmp_path = std::env::temp_dir().join(format!(
-            "pr-monitor-CR-M2-{}-state.json",
-            std::process::id()
-        ));
-        std::env::set_var("PR_MONITOR_STATE_FILE_OVERRIDE", &tmp_path);
-        seed_stale_recheck_state(&tmp_path);
+        let tmp = tempfile::tempdir().unwrap();
+        let state_path = tmp.path().join("state.json");
+        seed_stale_recheck_state(&state_path);
 
         let pr_info = pr_info_for_initial_review_park_test();
         let checker = std::path::PathBuf::from("dummy");
         let rate_limit_config = RateLimitConfig::default();
         let classifier_config = ClassifierConfig::default();
-        let ctx = make_default_test_ctx(&checker, &pr_info, &rate_limit_config, &classifier_config);
+        let ctx = make_default_test_ctx(
+            &checker,
+            &state_path,
+            &pr_info,
+            &rate_limit_config,
+            &classifier_config,
+        );
 
         let outcome = finalize_initial_review_park(&ctx);
-        let persisted = crate::state::read_state_from(&tmp_path).unwrap();
-
-        std::env::remove_var("PR_MONITOR_STATE_FILE_OVERRIDE");
-        let _ = std::fs::remove_file(&tmp_path);
+        let persisted = crate::state::read_state_from(&state_path).unwrap();
 
         assert_eq!(outcome.action, "parked_review_recheck");
         assert_eq!(
@@ -350,10 +336,8 @@ mod tests {
     /// or_else 被演算子の入れ替えバグを discriminate できる。
     #[test]
     fn finalize_initial_review_park_preserves_existing_fix_push_time() {
-        let _guard = env_override_lock();
         let tmp = tempfile::tempdir().unwrap();
         let state_path = tmp.path().join("state.json");
-        std::env::set_var("PR_MONITOR_STATE_FILE_OVERRIDE", &state_path);
 
         let mut seeded =
             PrMonitorState::new(Some(42), Some("o/r".into()), "2026-05-01T00:00:00Z".into());
@@ -370,14 +354,18 @@ mod tests {
         let checker = std::path::PathBuf::from("dummy");
         let rate_limit_config = RateLimitConfig::default();
         let classifier_config = ClassifierConfig::default();
-        let mut ctx =
-            make_default_test_ctx(&checker, &pr_info, &rate_limit_config, &classifier_config);
+        let mut ctx = make_default_test_ctx(
+            &checker,
+            &state_path,
+            &pr_info,
+            &rate_limit_config,
+            &classifier_config,
+        );
         let ctx_fix_push_time_must_lose = "2026-05-22T06:10:00Z";
         ctx.fix_push_time = Some(ctx_fix_push_time_must_lose);
 
         finalize_initial_review_park(&ctx);
         let persisted = crate::state::read_state_from(&state_path).unwrap();
-        std::env::remove_var("PR_MONITOR_STATE_FILE_OVERRIDE");
 
         assert_eq!(
             persisted.fix_push_time.as_deref(),
@@ -391,10 +379,8 @@ mod tests {
     /// `ctx.fix_push_time` の値で上書きしないことを検証する。
     #[test]
     fn finalize_review_recheck_park_preserves_existing_fix_push_time() {
-        let _guard = env_override_lock();
         let tmp = tempfile::tempdir().unwrap();
         let state_path = tmp.path().join("state.json");
-        std::env::set_var("PR_MONITOR_STATE_FILE_OVERRIDE", &state_path);
 
         let mut seeded =
             PrMonitorState::new(Some(42), Some("o/r".into()), "2026-05-01T00:00:00Z".into());
@@ -412,14 +398,18 @@ mod tests {
         let checker = std::path::PathBuf::from("dummy");
         let rate_limit_config = RateLimitConfig::default();
         let classifier_config = ClassifierConfig::default();
-        let mut ctx =
-            make_default_test_ctx(&checker, &pr_info, &rate_limit_config, &classifier_config);
+        let mut ctx = make_default_test_ctx(
+            &checker,
+            &state_path,
+            &pr_info,
+            &rate_limit_config,
+            &classifier_config,
+        );
         let ctx_fix_push_time_must_lose = "2026-05-22T06:10:00Z";
         ctx.fix_push_time = Some(ctx_fix_push_time_must_lose);
 
         finalize_review_recheck_park(&ctx);
         let persisted = crate::state::read_state_from(&state_path).unwrap();
-        std::env::remove_var("PR_MONITOR_STATE_FILE_OVERRIDE");
 
         assert_eq!(
             persisted.fix_push_time.as_deref(),
diff --git a/src/cli-pr-monitor/src/stages/poll/review_recheck_signal.rs b/src/cli-pr-monitor/src/stages/poll/review_recheck_signal.rs
index ecaaed77..ad132d92 100644
--- a/src/cli-pr-monitor/src/stages/poll/review_recheck_signal.rs
+++ b/src/cli-pr-monitor/src/stages/poll/review_recheck_signal.rs
@@ -238,6 +238,7 @@ mod tests {
         let classifier_config = ClassifierConfig::default();
         let ctx = PollContext {
             checker: &checker,
+            state_path: std::path::Path::new("unused"),
             push_time: "2026-05-01T00:00:00Z",
             fix_push_time: None,
             pr_info: &pr_info,
@@ -283,6 +284,7 @@ mod tests {
         let classifier_config = ClassifierConfig::default();
         let ctx = PollContext {
             checker: &checker,
+            state_path: std::path::Path::new("unused"),
             push_time: "2026-04-01T00:00:00Z",
             fix_push_time: None,
             pr_info: &pr_info,
diff --git a/src/cli-pr-monitor/src/state.rs b/src/cli-pr-monitor/src/state.rs
index 1bded3ee..78bcc3ba 100644
--- a/src/cli-pr-monitor/src/state.rs
+++ b/src/cli-pr-monitor/src/state.rs
@@ -153,15 +153,11 @@ impl PrMonitorState {
     }
 }
 
-/// state file の保存パスを返す。
+/// state file の保存パスを返す (本番デフォルト = `<exe>/pr-monitor-state.json`)。
 ///
-/// 通常は `<exe>/pr-monitor-state.json`。
-/// 環境変数 `PR_MONITOR_STATE_FILE_OVERRIDE` がセットされていればそのパスを優先する
-/// (T2-2 / fault injection test 用)。本番コードは env を設定しないため挙動変化なし。
+/// テストは override の env var ではなく、各関数に state path を直接注入する
+/// (順位 229: 共有グローバル可変状態を排し並列テスト間の競合を構造的に解消)。
 pub(crate) fn state_file_path() -> PathBuf {
-    if let Ok(path) = std::env::var("PR_MONITOR_STATE_FILE_OVERRIDE") {
-        return PathBuf::from(path);
-    }
     std::env::current_exe()
         .unwrap_or_default()
         .parent()
@@ -184,14 +180,6 @@ pub(crate) fn read_state_from(path: &Path) -> Option<PrMonitorState> {
     serde_json::from_str(&content).ok()
 }
 
-pub(crate) fn write_state(state: &PrMonitorState) -> Result<(), String> {
-    write_state_to(&state_file_path(), state)
-}
-
-pub(crate) fn read_state() -> Option<PrMonitorState> {
-    read_state_from(&state_file_path())
-}
-
 /// check-ci-coderabbit の JSON 出力から state を更新する
 pub(crate) fn update_state_from_check_result(
     state: &mut PrMonitorState,