diff --git a/docs/testing.md b/docs/testing.md
index bd00c7b..7daff71 100644
--- a/docs/testing.md
+++ b/docs/testing.md
@@ -109,10 +109,11 @@ scripts/test-integration --suite store --case '^TestStore' --run-id store-one-ca
 scripts/test-env status --run-id my-sample
 scripts/test-env collect --run-id my-sample
 scripts/test-env reset --run-id my-sample
-scripts/test-env reuse --run-id my-sample
-scripts/test-integration --suite sample --run-id my-sample --resume
-scripts/test-env reset --run-id my-sample
+scripts/test-env reuse --run-id my-sample --new-run-id my-sample-retry
+scripts/test-integration --suite sample --run-id my-sample-retry --resume
+scripts/test-env reset --run-id my-sample-retry
 scripts/test-env purge --run-id my-sample --execute --yes
+scripts/test-env purge --run-id my-sample-retry --execute --yes
 
 scripts/test-integration --suite store --run-id store-smoke
 scripts/test-env logs --run-id store-smoke
@@ -153,10 +154,17 @@ The Windows artifact is linked with the GUI subsystem (`-H=windowsgui`) so
 service, launcher, and tray startup do not flash a console. Human-facing modes
 still attach to a parent console explicitly when one exists.
 
-Suite output is capped at 1 MiB and stored as `artifacts/suite.log`. A failed
-run remains inspectable and can be moved back to `ready` with `recover`, then
-resumed with the same run ID and deterministic shuffle seed. Test-run cleanup
-never removes the shared Go module or build-cache volumes.
+Suite output is capped by the checked-in harness policy (10 MiB by default) and
+stored as `artifacts/suite.log`. A failed run remains inspectable and can be
+moved back to `ready` with `recover`, then resumed with the same run ID and
+deterministic shuffle seed only while its source definitions and working tree
+still match its manifest. `reuse` is intentionally different: after a reset or
+completed run, it creates a fresh manifest/run ID with the same layer, suite,
+and case selection, leaving the original evidence unchanged. `reset` refuses a
+running run or one with recorded owned runtime resources, removes only its
+ephemeral `runtime`, `pki`, and `scratch` directories, and retains the
+manifest, journal, reports, and artifacts. Test-run cleanup never removes the
+shared Go module or build-cache volumes.
 
 Each run owns only `.test-runs/<run-id>` and resources explicitly recorded in
 that run's versioned manifest. The journal is append-only and fsynced. `purge`
diff --git a/test/harness/harness.go b/test/harness/harness.go
index 6bb8710..9fc0fe2 100644
--- a/test/harness/harness.go
+++ b/test/harness/harness.go
@@ -548,6 +548,7 @@ func (h *harness) environmentCommand(command string, args []string) error {
 	flags := flag.NewFlagSet(command, flag.ContinueOnError)
 	flags.SetOutput(io.Discard)
 	runID := flags.String("run-id", "", "run ID")
+	newRunID := flags.String("new-run-id", "", "fresh run ID for reuse")
 	all := flags.Bool("all", false, "select every eligible run")
 	execute := flags.Bool("execute", false, "perform a destructive cleanup")
 	yes := flags.Bool("yes", false, "confirm destructive cleanup in noninteractive use")
@@ -557,6 +558,9 @@ func (h *harness) environmentCommand(command string, args []string) error {
 	if command != "purge" && (*all || *execute || *yes) {
 		return fmt.Errorf("%s does not accept cleanup options", command)
 	}
+	if command != "reuse" && *newRunID != "" {
+		return fmt.Errorf("%s does not accept --new-run-id", command)
+	}
 	if command == "purge" {
 		if (*runID == "") == (!*all) {
 			return errors.New("purge requires exactly one of --run-id or --all")
@@ -590,24 +594,72 @@ func (h *harness) environmentCommand(command string, args []string) error {
 	case "collect":
 		return h.collect(current)
 	case "recover":
+		if err := h.verifyResume(current); err != nil {
+			return err
+		}
 		if current.Phase != "interrupted" && current.Phase != "stopped" && current.Phase != "running" && current.Phase != "failed" {
 			return fmt.Errorf("run in phase %q does not need recovery", current.Phase)
 		}
 		return h.transition(current, "ready", "recover", "run recovered and ready to resume")
 	case "reuse":
-		if current.Phase != "reset" && current.Phase != "completed" && current.Phase != "ready" {
-			return fmt.Errorf("run in phase %q cannot be reused", current.Phase)
-		}
-		return h.transition(current, "ready", "reuse", "run retained for reuse")
+		return h.reuse(current, *newRunID)
 	case "stop":
 		return h.transition(current, "stopped", "stop", "owned runtime resources stopped")
 	case "reset":
-		return h.transition(current, "reset", "reset", "owned runtime state reset; manifest and journal retained")
+		return h.reset(current)
 	default:
 		return usageError()
 	}
 }
 
+func (h *harness) reuse(previous *manifest, newRunID string) error {
+	if previous.Phase != "reset" && previous.Phase != "completed" {
+		return fmt.Errorf("run in phase %q cannot be reused; reset or complete it first", previous.Phase)
+	}
+	if err := h.verifyResume(previous); err != nil {
+		return err
+	}
+	fresh, err := h.create(newRunID, previous.Layer, previous.Suite)
+	if err != nil {
+		return err
+	}
+	fresh.TestCase = previous.TestCase
+	if err := h.writeManifest(fresh); err != nil {
+		return err
+	}
+	if err := h.appendJournal(fresh.RunID, journalEntry{At: h.now(), Step: "reuse", Status: "passed", Detail: "fresh run created from immutable prior definitions", Data: map[string]any{"prior_run_id": previous.RunID}}); err != nil {
+		return err
+	}
+	fmt.Fprintf(h.out, "reused_from=%s new_run_id=%s\n", previous.RunID, fresh.RunID)
+	return nil
+}
+
+func (h *harness) reset(current *manifest) error {
+	if current.Phase == "running" {
+		return errors.New("refusing to reset a running run; stop it first")
+	}
+	if len(current.OwnedResources) != 0 {
+		return errors.New("refusing to reset a run with owned runtime resources; stop and reconcile them first")
+	}
+	for _, name := range []string{"runtime", "pki", "scratch"} {
+		path := filepath.Join(h.runDir(current.RunID), name)
+		info, err := os.Lstat(path)
+		if os.IsNotExist(err) {
+			continue
+		}
+		if err != nil {
+			return err
+		}
+		if info.Mode()&os.ModeSymlink != 0 || !info.IsDir() {
+			return fmt.Errorf("refusing unsafe reset path %s", path)
+		}
+		if err := os.RemoveAll(path); err != nil {
+			return err
+		}
+	}
+	return h.transition(current, "reset", "reset", "owned runtime scratch reset; manifest, journal, and reports retained")
+}
+
 func (h *harness) purgeCommand(runID string, all, execute, yes bool) error {
 	var candidates []*manifest
 	if all {
diff --git a/test/harness/harness_test.go b/test/harness/harness_test.go
index 0a5144b..62f8326 100644
--- a/test/harness/harness_test.go
+++ b/test/harness/harness_test.go
@@ -262,6 +262,86 @@ func TestBoundedSuiteLogAndFailedRunRecovery_BH_STORE_03(t *testing.T) {
 	}
 }
 
+func TestResetOnlyRemovesEphemeralState_HP_CFG_02(t *testing.T) {
+	t.Parallel()
+
+	h := &harness{root: t.TempDir(), now: time.Now, out: &bytes.Buffer{}}
+	current, err := h.create("reset-scratch", "integration", "sample")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, name := range []string{"runtime", "pki", "scratch", "artifacts"} {
+		path := filepath.Join(h.runDir(current.RunID), name)
+		if err := os.Mkdir(path, 0o700); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(filepath.Join(path, "marker"), []byte(name), 0o600); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := h.reset(current); err != nil {
+		t.Fatalf("reset: %v", err)
+	}
+	for _, name := range []string{"runtime", "pki", "scratch"} {
+		if _, err := os.Stat(filepath.Join(h.runDir(current.RunID), name)); !os.IsNotExist(err) {
+			t.Fatalf("reset retained %s: %v", name, err)
+		}
+	}
+	if _, err := os.Stat(filepath.Join(h.runDir(current.RunID), "artifacts", "marker")); err != nil {
+		t.Fatalf("reset removed preserved artifacts: %v", err)
+	}
+	loaded, err := h.load(current.RunID)
+	if err != nil || loaded.Phase != "reset" {
+		t.Fatalf("reset manifest = (%+v, %v)", loaded, err)
+	}
+
+	active, err := h.create("running-scratch", "integration", "sample")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := h.transition(active, "running", "start", "test"); err != nil {
+		t.Fatal(err)
+	}
+	if err := h.reset(active); err == nil {
+		t.Fatal("reset allowed an active run")
+	}
+}
+
+func TestReuseCreatesFreshRun_HP_CFG_03(t *testing.T) {
+	t.Parallel()
+
+	var output bytes.Buffer
+	h := &harness{root: t.TempDir(), now: time.Now, out: &output}
+	previous, err := h.create("prior-run", "e2e", "reconnect")
+	if err != nil {
+		t.Fatal(err)
+	}
+	previous.TestCase = "^TestReconnect$"
+	if err := h.writeManifest(previous); err != nil {
+		t.Fatal(err)
+	}
+	if err := h.transition(previous, "reset", "reset", "test"); err != nil {
+		t.Fatal(err)
+	}
+	if err := h.environmentCommand("reuse", []string{"--run-id", previous.RunID, "--new-run-id", "fresh-run"}); err != nil {
+		t.Fatalf("reuse: %v", err)
+	}
+	stillPrevious, err := h.load(previous.RunID)
+	if err != nil || stillPrevious.Phase != "reset" {
+		t.Fatalf("reuse mutated source run = (%+v, %v)", stillPrevious, err)
+	}
+	fresh, err := h.load("fresh-run")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if fresh.Layer != previous.Layer || fresh.Suite != previous.Suite || fresh.TestCase != previous.TestCase || fresh.Phase != "created" {
+		t.Fatalf("fresh reused manifest = %+v", fresh)
+	}
+	if !strings.Contains(output.String(), "reused_from=prior-run new_run_id=fresh-run") {
+		t.Fatalf("reuse output = %q", output.String())
+	}
+}
+
 func TestCoverageInventoryReferencesExistingTests_HP_CFG_01(t *testing.T) {
 	t.Parallel()