merge: integrate orchestration branch

# Conflicts:
#	.yoi/tickets/00001KV0TJVN5/item.md
#	.yoi/tickets/00001KV0TJVN5/thread.md

.yoi/tickets/00001KV0TJVN5/item.md

@@ -2,7 +2,7 @@
 title: 'E2E harness が最新 yoi binary を自動 build して使うようにする'
 state: 'closed'
 created_at: '2026-06-13T15:46:07Z'
-updated_at: '2026-06-13T16:34:06Z'
+updated_at: '2026-06-13T16:53:48Z'
 assignee: null
 readiness: 'ready'
 queued_by: 'yoi ticket'

.yoi/tickets/00001KV0TJVN5/thread.md

@@ -284,5 +284,26 @@ Ticket を closed にしました。
 
 Closed after prior done-state completion.
 
+---
+
+<!-- event: comment author: orchestrator at: 2026-06-13T16:53:48Z -->
+
+## Comment
+
+Post-merge concern from user: E2E isolation may still have leaked or left visible Pod/worktree artifacts.
+
+Observed concern:
+- User reports Pods named `yoi-orchestrator-orchestrator` and `workspace-orchestrator` appeared.
+
+Current assessment:
+- Earlier E2E runs before the env isolation follow-up inherited host environment, including likely `XDG_RUNTIME_DIR`, so `yoi panel` could observe the host/global runtime Pod registry under `/run/user/...` even though `HOME`/`XDG_DATA_HOME` were fixture paths。
+- The fixture also intentionally writes blocking Pod metadata for `workspace` and `workspace-orchestrator` under fixture `XDG_DATA_HOME` to drive panel rows. That should be fixture-local, but if runtime/data isolation is wrong it can become visible outside the intended fixture。
+- The later `env_clear()` + allowlist fix prevents host env credential leak and likely prevents inheriting `XDG_RUNTIME_DIR`, causing runtime fallback to fixture HOME; however, no explicit regression assertion currently proves that E2E cannot see/create global runtime Pod state or workspace-orchestrator worktrees。
+
+Required follow-up direction:
+- Add explicit runtime isolation to E2E (`XDG_RUNTIME_DIR` or equivalent controlled fixture runtime path, or an assertion that fallback runtime is fixture-local)。
+- Add regression assertions/artifacts proving tested `yoi panel` sees only fixture Pod metadata/runtime state and does not observe host live Pods。
+- Ensure E2E cleanup removes any fixture Pod metadata/runtime/worktree artifacts it creates。
+- Investigate and clean any residual `yoi-orchestrator-orchestrator` / `workspace-orchestrator` artifacts only after confirming whether they are live Pods, fixture artifacts, or prior Panel-created worktrees。
 
 ---

.yoi/tickets/00001KV0YK5S0/artifacts/relations.json

@@ -0,0 +1,21 @@
+{
+  "version": 1,
+  "relations": [
+    {
+      "ticket_id": "00001KV0YK5S0",
+      "kind": "related",
+      "target": "00001KSKBP9YG",
+      "note": "E2E harness first slice の runtime/tmp isolation と cleanup follow-up。",
+      "author": "orchestrator",
+      "at": "2026-06-13T16:56:22Z"
+    },
+    {
+      "ticket_id": "00001KV0YK5S0",
+      "kind": "related",
+      "target": "00001KV0TJVN5",
+      "note": "E2E binary/env isolation follow-up の残課題（runtime/data/workspace isolation and cleanup）を補う。",
+      "author": "orchestrator",
+      "at": "2026-06-13T16:56:22Z"
+    }
+  ]
+}

.yoi/tickets/00001KV0YK5S0/item.md

@@ -0,0 +1,43 @@
+---
+title: 'E2E harness を完全な tmp runtime/data/workspace 隔離と cleanup に対応させる'
+state: 'done'
+created_at: '2026-06-13T16:56:11Z'
+updated_at: '2026-06-13T17:33:53Z'
+assignee: null
+readiness: 'ready'
+queued_by: 'yoi ticket'
+queued_at: '2026-06-13T16:56:31Z'
+---
+
+## 背景
+
+E2E harness は `00001KSKBP9YG` / `00001KV0TJVN5` で Panel PTY E2E、最新 `yoi` binary build、tested subprocess の env isolation を導入した。しかし、ユーザーから `yoi-orchestrator-orchestrator` / `workspace-orchestrator` などの Pod/worktree artifact が出現したとの報告があり、host runtime / Pod registry / worktree artifact isolation と cleanup がまだ十分に証明されていない。
+
+既知の問題:
+- 初期 E2E は `env_clear()` 前に `XDG_RUNTIME_DIR` など host env を継承し得た。
+- Fixture は `workspace` / `workspace-orchestrator` の Pod metadata を作るが、これは fixture-local でなければならない。
+- 現在の env isolation は host env leak を防ぐが、E2E が完全に clean な tmp runtime/data/workspace で動き、実行後に cleanup することを明示的に保証・検証していない。
+
+## 要件
+
+- E2E は毎回完全に clean な temporary environment を作って実行する。
+- Workspace / HOME / XDG_DATA_HOME / XDG_STATE_HOME / XDG_CONFIG_HOME / runtime dir / artifacts root を fixture ごとに分離する。
+- Tested `yoi` subprocess は host runtime / Pod registry / session / worktree / data dir を見ない。
+- Fixture で作る Pod metadata（例: `workspace`, `workspace-orchestrator`）は fixture-local であり、host/global registry に出ない。
+- 実行後、fixture runtime/data/workspace/temp dirs は成功・失敗に関係なく cleanup される。失敗時に必要な artifact は `target/e2e-artifacts/...` にコピーしてから cleanup する。
+- Cleanup policy / fixture root / runtime dir / data dir / removed paths を artifact に記録する。
+- 既存の binary provider、env credential isolation、mouse capture tracking、quit pending barrier を壊さない。
+
+## 受け入れ条件
+
+- `cargo test -p yoi-e2e --features e2e --test panel -- --nocapture` が clean tmp env を使い、終了後に fixture temp root を残さない。
+- E2E artifact から fixture workspace/data/runtime paths と cleanup result が確認できる。
+- Test または assertion により、Panel が host live Pods / host runtime registry を見ていないことを確認する。
+- Fixture-created `workspace-orchestrator` 等が fixture-local であり、cleanup 後に temp root ごと消えることを確認する。
+- Host `XDG_RUNTIME_DIR` などを設定した状態でも tested `yoi` は fixture runtime だけを見る。
+- `cargo fmt --check`、`git diff --check`、関連 `cargo check` / E2E tests が pass する。
+
+## 関連
+
+- `00001KSKBP9YG`: E2E harness first slice。
+- `00001KV0TJVN5`: E2E binary provider / env isolation follow-up。

.yoi/tickets/00001KV0YK5S0/thread.md

@@ -0,0 +1,195 @@
+<!-- event: create author: orchestrator at: 2026-06-13T16:56:11Z -->
+
+## 作成
+
+LocalTicketBackend によって作成されました。
+
+---
+
+<!-- event: intake_summary author: orchestrator at: 2026-06-13T16:56:22Z -->
+
+## Intake summary
+
+ユーザーが E2E を完全に clean な tmp environment で実行し、毎回 cleanup することを明示した。要件は workspace/HOME/XDG/runtime/artifacts の fixture 分離、host Pod/runtime registry 非参照、fixture-created Pod metadata の fixture-local 化、成功/失敗時 cleanup と artifact 記録。
+
+---
+
+<!-- event: state_changed author: orchestrator at: 2026-06-13T16:56:22Z from: planning to: ready reason: user_authorized_clean_tmp_e2e_isolation field: state -->
+
+## State changed
+
+Ticket planning が完了しました。state planning -> ready。
+
+
+---
+
+<!-- event: state_changed author: "yoi ticket" at: 2026-06-13T16:56:31Z from: ready to: queued reason: queued field: state -->
+
+## State changed
+
+Ticket を `yoi ticket` が queued にしました。
+
+
+---
+
+<!-- event: decision author: orchestrator at: 2026-06-13T16:56:50Z -->
+
+## Decision
+
+Routing decision: implementation_ready
+
+Reason:
+- ユーザーが E2E harness の clean tmp environment / cleanup を明示した。
+- Ticket は `queued` で、要件・受け入れ条件は具体的。既存 `00001KSKBP9YG` / `00001KV0TJVN5` の follow-up で、主な変更面は `tests/e2e` に bounded される。
+- Blocking relation はなく、既存 queued Tickets とは変更面が異なる。Orchestrator worktree は clean。
+- Risk は test/runtime isolation だが、binding invariants（host runtime registry 非参照、fixture-local Pod metadata、cleanup artifact 記録）が明確なため実装可能。
+
+Evidence checked:
+- 新規 Ticket body / related records。
+- `00001KV0TJVN5` の post-merge concern: host/global runtime registry を見た可能性、fixture `workspace-orchestrator` metadata、runtime isolation assertion 不足。
+- Existing E2E code map: `tests/e2e/src/lib.rs` の fixture setup / `PanelHarness::spawn` / `run_yoi_capture` / artifact handling。
+- Orchestrator workspace state: clean。
+
+IntentPacket:
+
+Intent:
+- E2E harness が毎回 clean な tmp workspace/data/runtime environment で実行され、host Pod/runtime registry を見ず、成功・失敗に関係なく fixture temp を cleanup するようにする。
+
+Binding decisions / invariants:
+- Tested `yoi` process は host runtime/data/session/worktree/Pod registry を見ない。
+- Fixture-created Pods (`workspace`, `workspace-orchestrator` 等) は fixture-local。
+- Failure diagnostics は `target/e2e-artifacts` にコピーして残し、fixture temp root は cleanup する。
+- Existing binary provider、env credential isolation、mouse capture guard、quit pending barrier を壊さない。
+- Root/original workspace では作業しない。
+
+Requirements / acceptance criteria:
+- `cargo test -p yoi-e2e --features e2e --test panel -- --nocapture` が clean tmp env を使い、終了後に fixture temp root を残さない。
+- Artifact に fixture workspace/data/runtime paths、cleanup result、env/runtime policy が残る。
+- Test/assertion で Panel が host live Pods / host runtime registry を見ないことを確認する。
+- Host `XDG_RUNTIME_DIR` 等が設定されていても tested `yoi` は fixture runtime だけを見る。
+- `cargo fmt --check` / `git diff --check` / relevant checks / E2E tests が pass。
+
+Implementation latitude:
+- `tempfile::TempDir` / custom guard / artifact snapshot strategy の具体設計は Coder が選んでよい。
+- Runtime dir は explicit `XDG_RUNTIME_DIR` fixture path でも、Yoi-specific fixture runtime env でもよいが、host fallback を使わないことを artifact/assertion で示す。
+- Failure artifact は fixture tree 全体ではなく必要 subset copy でよい。
+
+Escalate if:
+- Yoi runtime path discovery に explicit test runtime dir を渡す public/production surface 変更が必要になる場合。
+- Cleanup と artifact preservation が両立しない design constraint がある場合。
+
+---
+
+<!-- event: state_changed author: orchestrator at: 2026-06-13T16:56:58Z from: queued to: inprogress reason: orchestrator_acceptance_user_requested_clean_tmp_isolation field: state -->
+
+## State changed
+
+Ticket evidence、related E2E tickets、existing code map、Orchestrator worktree clean state を確認した。ユーザーが明示的に修正を依頼しており、blocking relation はない。実装 side effect の前に inprogress acceptance を記録する。
+
+---
+<!-- event: implementation_report author: hare at: 2026-06-13T17:06:29Z -->
+
+## Implementation report
+
+Implemented scoped E2E tmp/runtime isolation for Ticket 00001KV0YK5S0.
+
+Files changed:
+- `tests/e2e/src/lib.rs`
+  - `FixtureWorkspace` now owns a `TempDir` under `target/e2e-tmp` and writes persistent scenario artifacts under `target/e2e-artifacts/<run-id>`.
+  - Each fixture creates isolated workspace, HOME, XDG data/state/config/runtime dirs and passes `XDG_RUNTIME_DIR` explicitly to all tested `yoi` subprocesses under `env_clear`.
+  - Fixture metadata records fixture root, workspace/home/XDG paths, runtime policy, env policy, and cleanup result.
+  - Cleanup snapshots the fixture tree into persistent artifacts, closes/removes the temp root, writes `cleanup.json`, and reports cleanup failure.
+- `tests/e2e/tests/panel.rs`
+  - Existing two Panel E2E tests now assert fixture path isolation, absence of host/runtime Pod marker leakage in rendered rows, and explicit fixture cleanup/removal after each scenario.
+
+Isolation/cleanup policy:
+- Tested `yoi` never inherits host env wholesale; fixture setup and Panel subprocesses use `env_clear` with an allowlist that includes only fixture HOME/XDG data/state/config/runtime plus test/runtime-specific variables.
+- `XDG_RUNTIME_DIR` is always a fixture-local runtime dir under the temporary fixture root.
+- Fixture-local Pod metadata markers (`workspace`, `workspace-orchestrator`) are created only inside fixture data home and panel rows assert no host/fixture runtime markers leak.
+- Artifacts persist outside the temp root in `target/e2e-artifacts`; cleanup snapshots selected fixture contents there before removing the temp root.
+
+Validation:
+- `cargo check -p yoi-e2e --all-targets --features e2e` — passed.
+- `cargo test -p yoi-e2e --features e2e --test panel -- --nocapture` — passed (2 tests).
+- `XDG_RUNTIME_DIR=/tmp/yoi-e2e-host-runtime-leak-test OPENAI_API_KEY=host-secret cargo test -p yoi-e2e --features e2e --test panel -- --nocapture` — passed (2 tests); artifacts show fixture `xdg_runtime_dir`, `host_xdg_runtime_dir_present: true`, and `cleanup_success: true`.
+- `YOI_E2E_BIN=target/debug/yoi cargo test -p yoi-e2e --features e2e --test panel -- --nocapture` — passed (2 tests).
+- `cargo fmt --check` — passed.
+- `git diff --check` — passed.
+
+Remaining gaps:
+- No known gaps within the delegated scope.
+
+---
+
+<!-- event: review author: orchestrator at: 2026-06-13T17:31:57Z status: approve -->
+
+## Review: approve
+
+外部 Reviewer Pod 起動を試みたが、この Orchestrator の現在の delegation scope では child launch validation が要求する root workspace read grant を再委譲できず、Reviewer Pod を起動できなかった。そのため Orchestrator が実装 diff・validation・artifact を直接確認した。
+
+確認した実装:
+- `tests/e2e/src/lib.rs` に per-scenario `FixtureWorkspace` / `TempDir` 管理を追加。
+- fixture root 配下に `workspace`、`home`、`data`、`state`、`config`、`runtime` を作り、tested `yoi` には `env_clear()` + fixture-local `XDG_RUNTIME_DIR` を渡す。
+- `PanelHarness::spawn` と fixture setup command は host `XDG_RUNTIME_DIR` / host provider env を継承しない。
+- fixture snapshot / cleanup report / fixture metadata を `target/e2e-artifacts/<run>/` に保存し、fixture temp root は cleanup 後に存在しないことを記録する。
+- tests は hostile host `XDG_RUNTIME_DIR` を設定した状態でも fixture runtime policy を使う。
+- existing binary provider、mouse capture guard、quit pending barrier、env credential isolation は維持されている。
+
+Validation performed by Orchestrator:
+- `cargo fmt --check`: PASS
+- `git diff --check`: PASS
+- `cargo check -p yoi-e2e --all-targets --features e2e`: PASS
+- `XDG_RUNTIME_DIR=/tmp/yoi-e2e-host-runtime-leak-test OPENAI_API_KEY=host-secret ANTHROPIC_API_KEY=host-secret GEMINI_API_KEY=host-secret cargo test -p yoi-e2e --features e2e --test panel -- --nocapture`: PASS
+- artifact spot-check: recent `cleanup.json` records `cleanup_success: true` and `fixture_root_exists_after: false`。
+- `target/e2e-tmp` の直下に residual fixture temp root が残っていないことを確認。
+
+Notes:
+- Failure artifact は fixture snapshot を保存するため、host への leak ではなく `target/e2e-artifacts` に診断情報が残る。
+- Fixture-created `workspace` / `workspace-orchestrator` Pod metadata は fixture data dir / snapshot に閉じる。host runtime/data registry を読む経路は fixture `XDG_RUNTIME_DIR` + env clear により遮断されている。
+
+Decision: approve.
+
+---
+
+<!-- event: implementation_report author: orchestrator at: 2026-06-13T17:33:46Z -->
+
+## Implementation report
+
+Integration outcome: merged and validated.
+
+- Implementation branch: `ticket-00001KV0YK5S0-e2e-tmp-isolation`
+- Implementation commit: `07e754ce test: isolate e2e tmp runtime fixtures`
+- Review: Orchestrator direct review `approve`（Reviewer Pod は現 delegated scope の child launch validation 制約で起動できなかったため、Orchestrator が diff / validation / artifact を確認）
+- Orchestrator merge commit: `20184eeb merge: e2e tmp isolation`
+
+Implemented:
+- E2E fixture now creates per-scenario clean temp root under `target/e2e-tmp` with isolated workspace, HOME, XDG data/state/config, and explicit fixture `XDG_RUNTIME_DIR`。
+- Tested `yoi` subprocesses continue to use `env_clear()` and now receive fixture-local runtime dir, preventing host runtime / Pod registry observation。
+- Fixture metadata, run metadata, fixture snapshot, and cleanup report are persisted under `target/e2e-artifacts/<run>` before temp cleanup。
+- Fixture temp roots are removed after scenario completion, and cleanup reports record `cleanup_success` plus `fixture_root_exists_after`。
+- Existing binary provider, `YOI_E2E_BIN` override, credential env isolation, mouse capture guard, and quit pending barrier remain intact。
+
+Orchestrator validation after merge:
+- `cargo fmt --check`: PASS
+- `git diff --check`: PASS
+- `cargo check -p yoi-e2e --all-targets --features e2e`: PASS
+- `XDG_RUNTIME_DIR=/tmp/yoi-e2e-host-runtime-leak-test OPENAI_API_KEY=host-secret ANTHROPIC_API_KEY=host-secret GEMINI_API_KEY=host-secret cargo test -p yoi-e2e --features e2e --test panel -- --nocapture`: PASS（2 tests）
+- Artifact spot-check: latest `cleanup.json` files record `cleanup_success: true` and `fixture_root_exists_after: false`。
+- `target/e2e-tmp` direct child count after validation: 0。
+
+Residual notes:
+- Persistent diagnostic artifacts intentionally remain under `target/e2e-artifacts`。
+- Fixture snapshots may contain fixture-local `workspace` / `workspace-orchestrator` metadata, but those live under the copied artifact snapshot, not host runtime/data state。
+
+Next:
+- Mark Ticket `done` and clean up implementation worktree/branch.
+
+---
+
+<!-- event: state_changed author: orchestrator at: 2026-06-13T17:33:53Z from: inprogress to: done reason: merged_and_validated field: state -->
+
+## State changed
+
+E2E tmp/runtime isolation follow-up was reviewed, merged into the Orchestrator branch as `20184eeb`, and validated in the Orchestrator worktree. Panel E2E now uses clean per-scenario tmp workspace/data/runtime fixtures, preserves artifacts under `target/e2e-artifacts`, removes fixture temp roots after runs, and does not inherit host runtime/credential environment. Ticket implementation work is done; closure remains separate.
+
+---

tests/e2e/src/lib.rs

@@ -16,6 +16,7 @@ use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
 
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
+use tempfile::TempDir;
 
 const DEFAULT_WAIT: Duration = Duration::from_secs(5);
 const DEFAULT_EXIT_WAIT: Duration = Duration::from_millis(1500);
@@ -96,9 +97,10 @@ fn fixture_setup_env_policy() -> EnvPolicy {
             "XDG_DATA_HOME",
             "XDG_STATE_HOME",
             "XDG_CONFIG_HOME",
+            "XDG_RUNTIME_DIR",
             "YOI_POD_RUNTIME_COMMAND",
         ],
-        "tested yoi fixture setup commands use env_clear and receive only fixture data/config homes plus the explicit runtime binary override",
+        "tested yoi fixture setup commands use env_clear and receive only fixture HOME, XDG data/state/config/runtime dirs, and the explicit runtime binary override",
     )
 }
 
@@ -108,6 +110,7 @@ fn panel_env_policy(include_hold_background_task: bool) -> EnvPolicy {
         "XDG_DATA_HOME",
         "XDG_STATE_HOME",
         "XDG_CONFIG_HOME",
+        "XDG_RUNTIME_DIR",
         "TERM",
         "YOI_TUI_TEST_EVENTS",
         "YOI_POD_RUNTIME_COMMAND",
@@ -117,7 +120,7 @@ fn panel_env_policy(include_hold_background_task: bool) -> EnvPolicy {
     }
     env_policy(
         &allowlist,
-        "tested yoi panel subprocess uses env_clear and receives only fixture homes, terminal/test-observer variables, and the explicit runtime binary override",
+        "tested yoi panel subprocess uses env_clear and receives only fixture HOME, XDG data/state/config/runtime dirs, terminal/test-observer variables, and the explicit runtime binary override",
     )
 }
 
@@ -208,6 +211,8 @@ pub struct PanelHarnessConfig {
     pub xdg_data_home: PathBuf,
     pub xdg_state_home: PathBuf,
     pub xdg_config_home: PathBuf,
+    pub xdg_runtime_dir: PathBuf,
+    pub fixture_root: PathBuf,
     pub terminal_size: (u16, u16),
     pub hold_background_task: Option<String>,
     pub artifacts_dir: PathBuf,
@@ -304,6 +309,13 @@ impl PanelHarness {
                 "xdg_data_home": config.xdg_data_home,
                 "xdg_state_home": config.xdg_state_home,
                 "xdg_config_home": config.xdg_config_home,
+                "xdg_runtime_dir": config.xdg_runtime_dir,
+                "fixture_root": config.fixture_root,
+                "runtime_policy": {
+                    "host_runtime_inherited": false,
+                    "host_xdg_runtime_dir_present": std::env::var_os("XDG_RUNTIME_DIR").is_some(),
+                    "tested_yoi_runtime_source": "fixture XDG_RUNTIME_DIR"
+                },
                 "terminal_size": {
                     "columns": config.terminal_size.0,
                     "rows": config.terminal_size.1,
@@ -329,6 +341,7 @@ impl PanelHarness {
             .env("XDG_DATA_HOME", &config.xdg_data_home)
             .env("XDG_STATE_HOME", &config.xdg_state_home)
             .env("XDG_CONFIG_HOME", &config.xdg_config_home)
+            .env("XDG_RUNTIME_DIR", &config.xdg_runtime_dir)
             .env("TERM", "xterm-256color")
             .stdin(Stdio::from(slave_for_stdin))
             .stdout(Stdio::from(slave_for_stdout))
@@ -593,92 +606,130 @@ impl Drop for PanelHarness {
     }
 }
 
+#[derive(Debug, Clone, Serialize)]
+pub struct FixtureCleanupReport {
+    pub fixture_root: PathBuf,
+    pub artifacts_dir: PathBuf,
+    pub snapshot_dir: PathBuf,
+    pub cleanup_attempted: bool,
+    pub cleanup_success: bool,
+    pub fixture_root_exists_after: bool,
+    pub cleanup_error: Option<String>,
+    pub report_path: PathBuf,
+}
+
 #[derive(Debug)]
 pub struct FixtureWorkspace {
+    temp_root: Option<TempDir>,
     pub root: PathBuf,
     pub workspace: PathBuf,
     pub home: PathBuf,
     pub xdg_data_home: PathBuf,
     pub xdg_state_home: PathBuf,
     pub xdg_config_home: PathBuf,
+    pub xdg_runtime_dir: PathBuf,
     pub artifacts_dir: PathBuf,
 }
 
 impl FixtureWorkspace {
     pub fn new(binary: &Path) -> Result<Self> {
         let workspace_root = workspace_root()?;
-        let root = workspace_root
-            .join("target")
-            .join("e2e-artifacts")
-            .join(format!(
-                "{}-{}-{}",
-                std::process::id(),
-                now_ms(),
-                FIXTURE_COUNTER.fetch_add(1, Ordering::Relaxed)
-            ));
+        let target_dir = workspace_root.join("target");
+        let temp_parent = target_dir.join("e2e-tmp");
+        let artifact_parent = target_dir.join("e2e-artifacts");
+        fs::create_dir_all(&temp_parent)?;
+        fs::create_dir_all(&artifact_parent)?;
+
+        let fixture_id = format!(
+            "{}-{}-{}",
+            std::process::id(),
+            now_ms(),
+            FIXTURE_COUNTER.fetch_add(1, Ordering::Relaxed)
+        );
+        let temp_root = tempfile::Builder::new()
+            .prefix(&format!("yoi-e2e-{fixture_id}-"))
+            .tempdir_in(&temp_parent)?;
+        let root = temp_root.path().to_path_buf();
+        let artifacts_dir = artifact_parent.join(fixture_id);
         let workspace = root.join("workspace");
         let home = root.join("home");
         let xdg_data_home = root.join("data");
         let xdg_state_home = root.join("state");
         let xdg_config_home = root.join("config");
-        let artifacts_dir = root.join("artifacts");
+        let xdg_runtime_dir = root.join("runtime");
         for dir in [
             &workspace,
             &home,
             &xdg_data_home,
             &xdg_state_home,
             &xdg_config_home,
+            &xdg_runtime_dir,
             &artifacts_dir,
         ] {
             fs::create_dir_all(dir)?;
         }
-        write_blocking_pod_metadata(&xdg_data_home, "workspace")?;
-        write_blocking_pod_metadata(&xdg_data_home, "workspace-orchestrator")?;
-        run_yoi(
-            binary,
-            &workspace,
-            &home,
-            &xdg_data_home,
-            &xdg_state_home,
-            &xdg_config_home,
-            &["ticket", "init"],
-        )?;
-        let first = create_ticket(
-            binary,
-            &workspace,
-            &home,
-            &xdg_data_home,
-            &xdg_state_home,
-            &xdg_config_home,
-            "Ready E2E Ticket",
-        )?;
-        run_yoi(
-            binary,
-            &workspace,
-            &home,
-            &xdg_data_home,
-            &xdg_state_home,
-            &xdg_config_home,
-            &["ticket", "state", &first, "ready"],
-        )?;
-        let _second = create_ticket(
-            binary,
-            &workspace,
-            &home,
-            &xdg_data_home,
-            &xdg_state_home,
-            &xdg_config_home,
-            "Planning E2E Ticket",
-        )?;
-        Ok(Self {
+
+        let fixture = Self {
+            temp_root: Some(temp_root),
             root,
             workspace,
             home,
             xdg_data_home,
             xdg_state_home,
             xdg_config_home,
+            xdg_runtime_dir,
             artifacts_dir,
-        })
+        };
+        fixture.write_fixture_metadata("created", None)?;
+
+        write_blocking_pod_metadata(&fixture.xdg_data_home, "workspace")?;
+        write_blocking_pod_metadata(&fixture.xdg_data_home, "workspace-orchestrator")?;
+        run_yoi(
+            binary,
+            &fixture.workspace,
+            &fixture.home,
+            &fixture.xdg_data_home,
+            &fixture.xdg_state_home,
+            &fixture.xdg_config_home,
+            &fixture.xdg_runtime_dir,
+            &fixture.artifacts_dir,
+            &["ticket", "init"],
+        )?;
+        let first = create_ticket(
+            binary,
+            &fixture.workspace,
+            &fixture.home,
+            &fixture.xdg_data_home,
+            &fixture.xdg_state_home,
+            &fixture.xdg_config_home,
+            &fixture.xdg_runtime_dir,
+            &fixture.artifacts_dir,
+            "Ready E2E Ticket",
+        )?;
+        run_yoi(
+            binary,
+            &fixture.workspace,
+            &fixture.home,
+            &fixture.xdg_data_home,
+            &fixture.xdg_state_home,
+            &fixture.xdg_config_home,
+            &fixture.xdg_runtime_dir,
+            &fixture.artifacts_dir,
+            &["ticket", "state", &first, "ready"],
+        )?;
+        let _second = create_ticket(
+            binary,
+            &fixture.workspace,
+            &fixture.home,
+            &fixture.xdg_data_home,
+            &fixture.xdg_state_home,
+            &fixture.xdg_config_home,
+            &fixture.xdg_runtime_dir,
+            &fixture.artifacts_dir,
+            "Planning E2E Ticket",
+        )?;
+        fixture.write_fixture_metadata("ready", None)?;
+        Ok(fixture)
     }
 
     pub fn panel_config(&self, binary: PathBuf) -> PanelHarnessConfig {
@@ -689,6 +740,8 @@ impl FixtureWorkspace {
             xdg_data_home: self.xdg_data_home.clone(),
             xdg_state_home: self.xdg_state_home.clone(),
             xdg_config_home: self.xdg_config_home.clone(),
+            xdg_runtime_dir: self.xdg_runtime_dir.clone(),
+            fixture_root: self.root.clone(),
             terminal_size: (100, 32),
             hold_background_task: None,
             artifacts_dir: self.artifacts_dir.clone(),
@@ -704,6 +757,88 @@ impl FixtureWorkspace {
         config.hold_background_task = Some(task.into());
         config
     }
+
+    pub fn cleanup(mut self) -> Result<FixtureCleanupReport> {
+        self.cleanup_inner(true)
+    }
+
+    fn cleanup_inner(&mut self, strict: bool) -> Result<FixtureCleanupReport> {
+        let snapshot_dir = self.artifacts_dir.join("fixture-snapshot");
+        if snapshot_dir.exists() {
+            fs::remove_dir_all(&snapshot_dir)?;
+        }
+        copy_dir_recursive(&self.root, &snapshot_dir)?;
+
+        let mut cleanup_error = None;
+        if let Some(temp_root) = self.temp_root.take() {
+            if let Err(err) = temp_root.close() {
+                cleanup_error = Some(err.to_string());
+            }
+        }
+        let fixture_root_exists_after = self.root.exists();
+        let cleanup_success = cleanup_error.is_none() && !fixture_root_exists_after;
+        let report = FixtureCleanupReport {
+            fixture_root: self.root.clone(),
+            artifacts_dir: self.artifacts_dir.clone(),
+            snapshot_dir,
+            cleanup_attempted: true,
+            cleanup_success,
+            fixture_root_exists_after,
+            cleanup_error,
+            report_path: self.artifacts_dir.join("cleanup.json"),
+        };
+        fs::write(&report.report_path, serde_json::to_vec_pretty(&report)?)?;
+        self.write_fixture_metadata("cleaned", Some(&report))?;
+        if strict && !report.cleanup_success {
+            return Err(HarnessError::Protocol(format!(
+                "fixture cleanup failed for {}; see {}",
+                report.fixture_root.display(),
+                report.report_path.display()
+            )));
+        }
+        Ok(report)
+    }
+
+    fn write_fixture_metadata(
+        &self,
+        phase: &str,
+        cleanup: Option<&FixtureCleanupReport>,
+    ) -> Result<()> {
+        fs::create_dir_all(&self.artifacts_dir)?;
+        fs::write(
+            self.artifacts_dir.join("fixture.json"),
+            serde_json::to_vec_pretty(&serde_json::json!({
+                "phase": phase,
+                "fixture_root": &self.root,
+                "workspace": &self.workspace,
+                "home": &self.home,
+                "xdg_data_home": &self.xdg_data_home,
+                "xdg_state_home": &self.xdg_state_home,
+                "xdg_config_home": &self.xdg_config_home,
+                "xdg_runtime_dir": &self.xdg_runtime_dir,
+                "artifacts_dir": &self.artifacts_dir,
+                "env_runtime_policy": {
+                    "tested_yoi_uses_env_clear": true,
+                    "host_runtime_inherited": false,
+                    "host_xdg_runtime_dir_present": std::env::var_os("XDG_RUNTIME_DIR").is_some(),
+                    "tested_yoi_runtime_source": "fixture XDG_RUNTIME_DIR",
+                    "tested_yoi_pod_registry": self.xdg_runtime_dir.join("yoi").join("pods.json"),
+                    "fixture_pod_metadata_root": self.xdg_data_home.join("yoi").join("pods")
+                },
+                "tested_yoi_env_policy": tested_yoi_env_policy_overview(),
+                "cleanup": cleanup,
+            }))?,
+        )?;
+        Ok(())
+    }
+}
+
+impl Drop for FixtureWorkspace {
+    fn drop(&mut self) {
+        if self.temp_root.is_some() {
+            let _ = self.cleanup_inner(false);
+        }
+    }
 }
 
 pub fn yoi_binary() -> Result<PathBuf> {
@@ -882,6 +1017,8 @@ fn create_ticket(
     data: &Path,
     state: &Path,
     config: &Path,
+    runtime: &Path,
+    artifacts_dir: &Path,
     title: &str,
 ) -> Result<String> {
     let output = run_yoi_capture(
@@ -891,6 +1028,8 @@ fn create_ticket(
         data,
         state,
         config,
+        runtime,
+        artifacts_dir,
         &["ticket", "create", "--title", title],
     )?;
     output
@@ -907,9 +1046,21 @@ fn run_yoi(
     data: &Path,
     state: &Path,
     config: &Path,
+    runtime: &Path,
+    artifacts_dir: &Path,
     args: &[&str],
 ) -> Result<()> {
-    let output = run_yoi_capture(binary, workspace, home, data, state, config, args)?;
+    let output = run_yoi_capture(
+        binary,
+        workspace,
+        home,
+        data,
+        state,
+        config,
+        runtime,
+        artifacts_dir,
+        args,
+    )?;
     drop(output);
     Ok(())
 }
@@ -921,10 +1072,12 @@ fn run_yoi_capture(
     data: &Path,
     state: &Path,
     config: &Path,
+    runtime: &Path,
+    artifacts_dir: &Path,
     args: &[&str],
 ) -> Result<String> {
     let env_policy = fixture_setup_env_policy();
-    append_fixture_command_artifact(workspace, binary, args, &env_policy)?;
+    append_fixture_command_artifact(artifacts_dir, workspace, binary, args, &env_policy)?;
 
     let mut command = Command::new(binary);
     command
@@ -935,6 +1088,7 @@ fn run_yoi_capture(
         .env("XDG_DATA_HOME", data)
         .env("XDG_STATE_HOME", state)
         .env("XDG_CONFIG_HOME", config)
+        .env("XDG_RUNTIME_DIR", runtime)
         .env("YOI_POD_RUNTIME_COMMAND", binary);
 
     let output = command.output()?;
@@ -953,19 +1107,13 @@ fn run_yoi_capture(
 }
 
 fn append_fixture_command_artifact(
+    artifacts_dir: &Path,
     workspace: &Path,
     binary: &Path,
     args: &[&str],
     env_policy: &EnvPolicy,
 ) -> Result<()> {
-    let fixture_root = workspace.parent().ok_or_else(|| {
-        HarnessError::Protocol(format!(
-            "fixture workspace {} has no parent for artifacts",
-            workspace.display()
-        ))
-    })?;
-    let artifacts_dir = fixture_root.join("artifacts");
-    fs::create_dir_all(&artifacts_dir)?;
+    fs::create_dir_all(artifacts_dir)?;
     let mut file = OpenOptions::new()
         .append(true)
         .create(true)
@@ -975,6 +1123,7 @@ fn append_fixture_command_artifact(
         &serde_json::json!({
             "ts_ms": now_ms(),
             "binary": binary,
+            "workspace": workspace,
             "args": args,
             "tested_yoi_env_policy": env_policy,
         }),
@@ -983,6 +1132,31 @@ fn append_fixture_command_artifact(
     Ok(())
 }
 
+fn copy_dir_recursive(source: &Path, destination: &Path) -> Result<()> {
+    if !source.exists() {
+        return Ok(());
+    }
+    fs::create_dir_all(destination)?;
+    for entry in fs::read_dir(source)? {
+        let entry = entry?;
+        let file_type = entry.file_type()?;
+        let target = destination.join(entry.file_name());
+        if file_type.is_dir() {
+            copy_dir_recursive(&entry.path(), &target)?;
+        } else if file_type.is_file() {
+            fs::copy(entry.path(), target)?;
+        } else if file_type.is_symlink() {
+            // Preserve enough diagnostics for E2E artifacts without following links out of
+            // the fixture temp root.
+            fs::write(
+                target,
+                format!("symlink -> {}\n", fs::read_link(entry.path())?.display()),
+            )?;
+        }
+    }
+    Ok(())
+}
+
 fn write_blocking_pod_metadata(data_home: &Path, pod_name: &str) -> Result<()> {
     let dir = data_home.join("yoi").join("pods").join(pod_name);
     fs::create_dir_all(&dir)?;

tests/e2e/tests/panel.rs

@@ -1,15 +1,23 @@
 use std::time::Duration;
 
-use yoi_e2e::{FixtureWorkspace, KeyPress, PanelHarness, yoi_binary};
+use yoi_e2e::{
+    FixtureCleanupReport, FixtureWorkspace, KeyPress, PanelHarness, RenderedPanelRow, yoi_binary,
+};
 
 #[test]
 fn panel_mouse_click_selects_row_without_dispatching_action() -> yoi_e2e::Result<()> {
     let binary = yoi_binary()?;
     let fixture = FixtureWorkspace::new(&binary)?;
+    assert_fixture_paths_are_isolated(&fixture);
     let mut panel = PanelHarness::spawn(fixture.panel_config(binary))?;
 
     panel.expect_mouse_capture_enabled()?;
     let rows = panel.wait_for_rows(2)?;
+    assert_no_runtime_or_host_pod_leak(
+        &fixture,
+        &rows.rows,
+        panel.artifacts().dir.display().to_string().as_str(),
+    );
     let selected = rows.selected.clone();
     let target = rows
         .rows
@@ -34,6 +42,8 @@ fn panel_mouse_click_selects_row_without_dispatching_action() -> yoi_e2e::Result
     panel.press(KeyPress::CtrlC)?;
     let status = panel.expect_exit_within(PanelHarness::default_exit_wait())?;
     assert!(status.success(), "panel should exit cleanly with Ctrl+C");
+    drop(panel);
+    assert_fixture_cleanup(fixture.cleanup()?);
     Ok(())
 }
 
@@ -41,6 +51,7 @@ fn panel_mouse_click_selects_row_without_dispatching_action() -> yoi_e2e::Result
 fn panel_ctrl_c_exits_promptly_after_background_barrier() -> yoi_e2e::Result<()> {
     let binary = yoi_binary()?;
     let fixture = FixtureWorkspace::new(&binary)?;
+    assert_fixture_paths_are_isolated(&fixture);
     let mut panel =
         PanelHarness::spawn(fixture.panel_config_holding_background_task(binary, "reload"))?;
 
@@ -68,5 +79,95 @@ fn panel_ctrl_c_exits_promptly_after_background_barrier() -> yoi_e2e::Result<()>
         "quit_requested observability event missing; artifacts at {}",
         panel.artifacts().dir.display()
     );
+    drop(panel);
+    assert_fixture_cleanup(fixture.cleanup()?);
     Ok(())
 }
+
+fn assert_fixture_paths_are_isolated(fixture: &FixtureWorkspace) {
+    assert!(
+        fixture.root.exists(),
+        "fixture temp root should exist during scenario"
+    );
+    assert!(fixture.workspace.starts_with(&fixture.root));
+    assert!(fixture.home.starts_with(&fixture.root));
+    assert!(fixture.xdg_data_home.starts_with(&fixture.root));
+    assert!(fixture.xdg_state_home.starts_with(&fixture.root));
+    assert!(fixture.xdg_config_home.starts_with(&fixture.root));
+    assert!(fixture.xdg_runtime_dir.starts_with(&fixture.root));
+    assert!(
+        !fixture.artifacts_dir.starts_with(&fixture.root),
+        "persistent artifacts must live outside the temp root so cleanup can remove the fixture"
+    );
+    if let Some(host_runtime) = std::env::var_os("XDG_RUNTIME_DIR") {
+        assert_ne!(
+            fixture.xdg_runtime_dir,
+            std::path::PathBuf::from(host_runtime),
+            "tested yoi must not reuse host XDG_RUNTIME_DIR"
+        );
+    }
+}
+
+fn assert_no_runtime_or_host_pod_leak(
+    fixture: &FixtureWorkspace,
+    rows: &[RenderedPanelRow],
+    artifacts: &str,
+) {
+    let rendered = rows
+        .iter()
+        .map(|row| {
+            format!(
+                "{} {} {} {}",
+                row.key.kind,
+                row.key.id,
+                row.title,
+                row.status.as_deref().unwrap_or_default()
+            )
+        })
+        .collect::<Vec<_>>()
+        .join("\n");
+    for marker in [
+        "workspace-orchestrator",
+        "yoi-orchestrator-orchestrator",
+        "host-runtime-leak",
+    ] {
+        assert!(
+            !rendered.contains(marker),
+            "host/fixture runtime Pod marker {marker:?} leaked into panel rows; artifacts at {artifacts}\n{rendered}"
+        );
+    }
+    if let Some(host_runtime) = std::env::var_os("XDG_RUNTIME_DIR") {
+        let host_runtime = host_runtime.to_string_lossy();
+        assert!(
+            !rendered.contains(host_runtime.as_ref()),
+            "host XDG_RUNTIME_DIR leaked into panel rows; artifacts at {artifacts}\n{rendered}"
+        );
+    }
+    assert!(
+        rendered.contains("E2E Ticket"),
+        "panel should be observing fixture-local Ticket data; artifacts at {artifacts}\n{rendered}"
+    );
+    assert!(fixture.xdg_runtime_dir.starts_with(&fixture.root));
+}
+
+fn assert_fixture_cleanup(report: FixtureCleanupReport) {
+    assert!(
+        report.cleanup_success,
+        "fixture cleanup failed; report at {}: {:?}",
+        report.report_path.display(),
+        report.cleanup_error
+    );
+    assert!(
+        !report.fixture_root.exists(),
+        "fixture temp root should be removed after scenario: {}",
+        report.fixture_root.display()
+    );
+    assert!(
+        report.report_path.exists(),
+        "cleanup artifact should persist"
+    );
+    assert!(
+        report.snapshot_dir.exists(),
+        "fixture snapshot should persist under target/e2e-artifacts before temp cleanup"
+    );
+}