fix(skills): guard pruneSkillBackups against non-DWS directories

Restrict backup pruning to directories whose names match the DWS stamp
format (YYYYmmdd-HHMMSS with optional -N suffix) across all 8 installer
surfaces (Go, npm, 4 shell, 2 PowerShell). Unknown directories in
~/.dws/skill-backups are now preserved. Also fixes Windows coverage test
portability and covers the remaining macOS changed-code gap (retire
warning loop in runUpgrade).

.github/workflows/ci.yml

@@ -512,6 +512,10 @@ jobs:
         if: steps.classify.outputs.changelog_only != 'true' && steps.classify.outputs.docs_only != 'true'
         run: node .github/reviewer-routing.test.js
 
+      - name: Test npm installer smoke (prune, backup, publish)
+        if: steps.classify.outputs.changelog_only != 'true' && steps.classify.outputs.docs_only != 'true'
+        run: node test/scripts/install_js_smoke.mjs
+
   test-focused:
     name: "Test (focused: ${{ matrix.shard }})"
     needs: lint

build/npm/install.js

@@ -163,9 +163,21 @@ const SKILL_BACKUP_KEEP = 5;
 // transaction still needs them to roll back.
 const currentRunBackupRoots = new Set();
 
+// skillBackupStampPattern matches only directory names DWS itself writes:
+// UTC YYYYmmdd-HHMMSS, with an optional -N collision suffix. Any other entry
+// in the backup root is foreign (user data, unrelated tooling) and must be
+// left untouched, so pruning is restricted to names it can prove DWS created.
+const skillBackupStampPattern = /^[0-9]{8}-[0-9]{6}(-[0-9]+)?$/;
+
+function isSkillBackupStamp(name) {
+  return skillBackupStampPattern.test(name);
+}
+
 // pruneSkillBackups removes the oldest stamped backup directories once more
-// than SKILL_BACKUP_KEEP remain. Stamps sort lexicographically in
-// chronological order (`YYYYmmdd-HHMMSS`), so name order is age order.
+// than SKILL_BACKUP_KEEP remain. Only directories whose names match the DWS
+// backup stamp format are candidates; unknown directories are preserved.
+// Stamps sort lexicographically in chronological order (`YYYYmmdd-HHMMSS`),
+// so name order is age order.
 function pruneSkillBackups(homeDir) {
   const root = path.join(homeDir, ".dws", "skill-backups");
   let entries;
@@ -176,7 +188,7 @@ function pruneSkillBackups(homeDir) {
     throw err;
   }
   const names = entries
-    .filter((entry) => entry.isDirectory())
+    .filter((entry) => entry.isDirectory() && isSkillBackupStamp(entry.name))
     .map((entry) => entry.name)
     .sort((a, b) => Buffer.from(a).compare(Buffer.from(b)));
   let excess = names.length - SKILL_BACKUP_KEEP;
@@ -1401,6 +1413,8 @@ module.exports = {
   UPSTREAM_AGENTS,
   resolvedAgentTargets,
   agentTargetDetected,
+  isSkillBackupStamp,
+  pruneSkillBackups,
   backupAndRemoveSkillDir,
   copyPathLexicallySync,
   movePathRecoverablySync,

internal/app/upgrade_full_coverage_test.go

@@ -292,6 +292,12 @@ func TestCrossPlatformCoverageRunUpgradeAllStagesCoverage(t *testing.T) {
 			if stage == "install-failed-dir" {
 				return &upgradepkg.SkillUpgradeResult{Results: []upgradepkg.SkillDirResult{{Dir: "/failed", Status: upgradepkg.SkillDirFailed, Err: fail}}}, nil
 			}
+			if stage == "install-retire-warning" {
+				return &upgradepkg.SkillUpgradeResult{Results: []upgradepkg.SkillDirResult{
+					{Dir: "/ok", Status: upgradepkg.SkillDirOK},
+					{Dir: "/stale", Status: upgradepkg.SkillDirRetireWarning, Err: errors.New("retirement refused")},
+				}}, nil
+			}
 			return &upgradepkg.SkillUpgradeResult{Results: []upgradepkg.SkillDirResult{{Dir: "/ok", Status: upgradepkg.SkillDirOK}}}, nil
 		}
 	}
@@ -300,7 +306,7 @@ func TestCrossPlatformCoverageRunUpgradeAllStagesCoverage(t *testing.T) {
 		"ensure", "tag-error", "latest-error", "not-needed", "cancel", "find-binary", "temp-fallback", "temp-both",
 		"backup", "checksum-download", "checksum-read", "binary-download", "skills-download", "verify-binary", "verify-skills",
 		"extract-binary", "extract-tar", "binary-missing", "validate", "extract-skills", "skill-missing", "replace", "install", "install-failed-dir",
-		"success", "success-no-skills",
+		"success", "success-no-skills", "install-retire-warning",
 	} {
 		t.Run(stage, func(t *testing.T) {
 			configure(stage)
@@ -330,14 +336,14 @@ func TestCrossPlatformCoverageRunUpgradeAllStagesCoverage(t *testing.T) {
 				opts.skipSkills = true
 			}
 			err := runUpgrade(context.Background(), opts)
-			wantError := stage != "not-needed" && stage != "cancel" && stage != "backup" && stage != "checksum-download" && stage != "checksum-read" && stage != "success" && stage != "success-no-skills"
+			wantError := stage != "not-needed" && stage != "cancel" && stage != "backup" && stage != "checksum-download" && stage != "checksum-read" && stage != "success" && stage != "success-no-skills" && stage != "install-retire-warning"
 			if wantError && err == nil {
 				t.Fatalf("stage %s succeeded", stage)
 			}
 			if !wantError && err != nil {
 				t.Fatalf("stage %s failed: %v", stage, err)
 			}
-			if (stage == "success" || stage == "success-no-skills") && !rb.cleaned {
+			if (stage == "success" || stage == "success-no-skills" || stage == "install-retire-warning") && !rb.cleaned {
 				t.Fatal("successful upgrade did not clean backups")
 			}
 			if stage == "success" {

internal/upgrade/paths.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"regexp"
 	"runtime"
 	"sort"
 	"strings"
@@ -383,9 +384,22 @@ func buildUpgradeProvenanceRecords(root string, names []string, version string)
 // backups are kept.
 const skillBackupKeep = 5
 
+// skillBackupStampRegexp matches only directory names DWS itself writes:
+// UTC YYYYmmdd-HHMMSS, with an optional -N collision suffix. Any other entry
+// in the backup root is foreign (user data, unrelated tooling) and must be
+// left untouched, so pruning is restricted to names it can prove DWS created.
+var skillBackupStampRegexp = regexp.MustCompile(`^[0-9]{8}-[0-9]{6}(-[0-9]+)?$`)
+
+// isSkillBackupStamp reports whether name is a DWS-created backup stamp.
+func isSkillBackupStamp(name string) bool {
+	return skillBackupStampRegexp.MatchString(name)
+}
+
 // pruneSkillBackups removes the oldest backup directories when more than
-// skillBackupKeep remain. Best-effort: a removal failure never aborts, but
-// pruning failures are reported so callers can warn the user.
+// skillBackupKeep remain. Only directories whose names match the DWS backup
+// stamp format are candidates; unknown directories are preserved. Best-effort:
+// a removal failure never aborts, but pruning failures are reported so
+// callers can warn the user.
 func pruneSkillBackups(homeDir string) error {
 	root := filepath.Join(homeDir, skillBackupSubdir)
 	entries, err := upgradeReadDir(root)
@@ -397,7 +411,7 @@ func pruneSkillBackups(homeDir string) error {
 	}
 	names := make([]string, 0, len(entries))
 	for _, e := range entries {
-		if e.IsDir() {
+		if e.IsDir() && isSkillBackupStamp(e.Name()) {
 			names = append(names, e.Name())
 		}
 	}

internal/upgrade/paths_multi_test.go

@@ -877,6 +877,60 @@ func TestCrossPlatformCoveragePruneSkillBackupsEdges(t *testing.T) {
 	testseam.Swap(t, &upgradeRemoveAll, os.RemoveAll)
 }
 
+// TestCrossPlatformCoveragePruneSkillBackupsPreservesUnknown pins that
+// pruneSkillBackups only retires directories whose names match the DWS backup
+// stamp format. Any foreign directory in the backup root must survive even when
+// more than skillBackupKeep stamped backups exist.
+func TestCrossPlatformCoveragePruneSkillBackupsPreservesUnknown(t *testing.T) {
+	home := t.TempDir()
+	root := filepath.Join(home, skillBackupSubdir)
+	for i := 0; i < skillBackupKeep+2; i++ {
+		if err := os.MkdirAll(filepath.Join(root, fmt.Sprintf("20260910-00000%d", i)), 0o755); err != nil {
+			t.Fatal(err)
+		}
+	}
+	// A collision-suffixed stamp is still a valid DWS backup and is eligible.
+	if err := os.MkdirAll(filepath.Join(root, "20260910-000000-7"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	unknown := []string{
+		"user-personal-backup",
+		"20260910-000000-abc", // stamp-shaped but non-numeric suffix
+		"20260910-00000",      // too short
+		"notes",
+	}
+	for _, name := range unknown {
+		if err := os.MkdirAll(filepath.Join(root, name), 0o755); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	if err := pruneSkillBackups(home); err != nil {
+		t.Fatalf("pruneSkillBackups() error = %v", err)
+	}
+
+	for _, name := range unknown {
+		if _, err := os.Stat(filepath.Join(root, name)); err != nil {
+			t.Errorf("unknown backup entry %s must be preserved, stat err=%v", name, err)
+		}
+	}
+	// Only stamped backups beyond skillBackupKeep are pruned; foreign entries
+	// are excluded from the count, so the stamp total stays at skillBackupKeep.
+	entries, err := os.ReadDir(root)
+	if err != nil {
+		t.Fatal(err)
+	}
+	stamps := 0
+	for _, e := range entries {
+		if isSkillBackupStamp(e.Name()) {
+			stamps++
+		}
+	}
+	if stamps != skillBackupKeep {
+		t.Errorf("stamped backups after prune = %d, want %d", stamps, skillBackupKeep)
+	}
+}
+
 // TestCrossPlatformCoverageResolveSkillSrcLayouts pins every fallback branch of
 // the mono-source resolver and the multi-bundle child lookup.
 func TestCrossPlatformCoverageResolveSkillSrcLayouts(t *testing.T) {

internal/upgrade/skill_path_move_unix_test.go

@@ -10,3 +10,7 @@ import (
 func testCrossDeviceError() error {
 	return &os.LinkError{Op: "rename", Old: "src", New: "dst", Err: syscall.EXDEV}
 }
+
+func testNoReplaceUnsupportedErrors() []error {
+	return []error{syscall.EINVAL, syscall.ENOSYS, errNoReplaceRenameUnsupported}
+}

internal/upgrade/skill_path_move_windows_test.go

@@ -13,6 +13,10 @@ func testCrossDeviceError() error {
 	return &os.LinkError{Op: "rename", Old: "src", New: "dst", Err: windows.ERROR_NOT_SAME_DEVICE}
 }
 
+func testNoReplaceUnsupportedErrors() []error {
+	return []error{errNoReplaceRenameUnsupported}
+}
+
 func TestCrossPlatformCoverageWindowsCrossDeviceError(t *testing.T) {
 	if !isCrossDeviceError(testCrossDeviceError()) {
 		t.Fatal("ERROR_NOT_SAME_DEVICE must enter the cross-device fallback")

internal/upgrade/skill_publish_rename_test.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"os"
 	"path/filepath"
-	"syscall"
 	"testing"
 
 	"github.com/DingTalk-Real-AI/dingtalk-workspace-cli/internal/testseam"
@@ -15,7 +14,7 @@ import (
 // Those installs must still publish, and must still refuse to clobber an
 // occupied destination.
 func TestCrossPlatformCoverageNoReplaceRenameFallback(t *testing.T) {
-	unsupported := []error{syscall.EINVAL, syscall.ENOSYS, errNoReplaceRenameUnsupported}
+	unsupported := testNoReplaceUnsupportedErrors()
 
 	t.Run("publishes when the filesystem rejects the flag", func(t *testing.T) {
 		for _, unsupportedErr := range unsupported {
@@ -47,7 +46,7 @@ func TestCrossPlatformCoverageNoReplaceRenameFallback(t *testing.T) {
 				t.Fatal(err)
 			}
 		}
-		testseam.Swap(t, &skillPathRenameNoReplaceAtomic, func(string, string) error { return syscall.EINVAL })
+		testseam.Swap(t, &skillPathRenameNoReplaceAtomic, func(string, string) error { return errNoReplaceRenameUnsupported })
 		err := renameSkillPathNoReplace(source, destination)
 		if !errors.Is(err, os.ErrExist) {
 			t.Fatalf("occupied destination must report ErrExist, got %v", err)
@@ -80,8 +79,9 @@ func TestCrossPlatformCoverageNoReplaceRenameFallback(t *testing.T) {
 	})
 
 	t.Run("cross-device errors still reach the copy fallback", func(t *testing.T) {
-		if isNoReplaceRenameUnsupported(syscall.EXDEV) {
-			t.Fatal("EXDEV must not be treated as an unsupported flag")
+		crossDevice := testCrossDeviceError()
+		if isNoReplaceRenameUnsupported(crossDevice) {
+			t.Fatal("cross-device error must not be treated as an unsupported flag")
 		}
 		dir := t.TempDir()
 		source := filepath.Join(dir, "source")
@@ -95,7 +95,7 @@ func TestCrossPlatformCoverageNoReplaceRenameFallback(t *testing.T) {
 		original := skillPathRenameNoReplaceAtomic
 		testseam.Swap(t, &skillPathRenameNoReplaceAtomic, func(from, to string) error {
 			if from == source {
-				return syscall.EXDEV
+				return crossDevice
 			}
 			return original(from, to)
 		})

scripts/install-devapp.ps1

@@ -290,7 +290,11 @@ $script:DevSkillBackupRootsThisRun = [System.Collections.Generic.HashSet[string]
 function Remove-OldDevSkillBackups {
     $root = Join-Path $HOME ".dws\skill-backups"
     if (!(Test-Path -LiteralPath $root -PathType Container)) { return }
+    # Only directories whose names match the DWS backup stamp format (UTC
+    # yyyyMMdd-HHmmss, optional -N collision suffix) are candidates; any
+    # other entry is foreign data and is preserved.
     $dirs = @(Get-ChildItem -LiteralPath $root -Directory -Force -ErrorAction SilentlyContinue |
+        Where-Object { $_.Name -match '^[0-9]{8}-[0-9]{6}(-[0-9]+)?$' } |
         Sort-Object -Property Name)
     $excess = $dirs.Count - $DevSkillBackupKeep
     foreach ($dir in $dirs) {

scripts/install-devapp.sh

@@ -121,12 +121,34 @@ backup_skill_dir() {
 # YYYYmmdd-HHMMSS, so the oldest sort first. Best-effort: a removal failure is
 # reported and never fatal.
 SKILL_BACKUP_KEEP=5
+
+# is_skill_backup_stamp accepts only directory names DWS itself writes: UTC
+# YYYYmmdd-HHMMSS, with an optional -N collision suffix. Any other entry in
+# the backup root is foreign (user data, unrelated tooling) and is preserved
+# so pruning can never remove a directory it cannot prove DWS created.
+is_skill_backup_stamp() {
+  case "$1" in
+    [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]-[0-9][0-9][0-9][0-9][0-9][0-9])
+      return 0 ;;
+    [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]-[0-9][0-9][0-9][0-9][0-9][0-9]-*)
+      # base stamp is YYYYMMDD-HHMMSS (15 chars) + suffix dash (16th); strip
+      # those 16 chars and require the remainder to be all digits.
+      _isbs_suffix="${1#????????????????}"
+      case "$_isbs_suffix" in
+        ""|*[!0-9]*) return 1 ;;
+      esac
+      return 0 ;;
+  esac
+  return 1
+}
+
 prune_skill_backups() {
   prune_root="$HOME/.dws/skill-backups"
   [ -d "$prune_root" ] || return 0
   prune_total=0
   for prune_entry in "$prune_root"/*; do
     [ -d "$prune_entry" ] || continue
+    is_skill_backup_stamp "${prune_entry##*/}" || continue
     prune_total=$((prune_total + 1))
   done
   [ "$prune_total" -gt "$SKILL_BACKUP_KEEP" ] || return 0
@@ -134,6 +156,7 @@ prune_skill_backups() {
   prune_seen=0
   for prune_entry in "$prune_root"/*; do
     [ -d "$prune_entry" ] || continue
+    is_skill_backup_stamp "${prune_entry##*/}" || continue
     prune_seen=$((prune_seen + 1))
     [ "$prune_seen" -le "$prune_drop" ] || break
     rm -rf "$prune_entry" || printf '  ⚠️  旧 Skill 备份清理失败: %s\n' "$prune_entry" >&2

scripts/install-event.sh

@@ -190,12 +190,34 @@ backup_skill_dir() {
 # YYYYmmdd-HHMMSS, so the oldest sort first. Best-effort: a removal failure is
 # reported and never fatal.
 SKILL_BACKUP_KEEP=5
+
+# is_skill_backup_stamp accepts only directory names DWS itself writes: UTC
+# YYYYmmdd-HHMMSS, with an optional -N collision suffix. Any other entry in
+# the backup root is foreign (user data, unrelated tooling) and is preserved
+# so pruning can never remove a directory it cannot prove DWS created.
+is_skill_backup_stamp() {
+  case "$1" in
+    [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]-[0-9][0-9][0-9][0-9][0-9][0-9])
+      return 0 ;;
+    [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]-[0-9][0-9][0-9][0-9][0-9][0-9]-*)
+      # base stamp is YYYYMMDD-HHMMSS (15 chars) + suffix dash (16th); strip
+      # those 16 chars and require the remainder to be all digits.
+      _isbs_suffix="${1#????????????????}"
+      case "$_isbs_suffix" in
+        ""|*[!0-9]*) return 1 ;;
+      esac
+      return 0 ;;
+  esac
+  return 1
+}
+
 prune_skill_backups() {
   prune_root="$HOME/.dws/skill-backups"
   [ -d "$prune_root" ] || return 0
   prune_total=0
   for prune_entry in "$prune_root"/*; do
     [ -d "$prune_entry" ] || continue
+    is_skill_backup_stamp "${prune_entry##*/}" || continue
     prune_total=$((prune_total + 1))
   done
   [ "$prune_total" -gt "$SKILL_BACKUP_KEEP" ] || return 0
@@ -203,6 +225,7 @@ prune_skill_backups() {
   prune_seen=0
   for prune_entry in "$prune_root"/*; do
     [ -d "$prune_entry" ] || continue
+    is_skill_backup_stamp "${prune_entry##*/}" || continue
     prune_seen=$((prune_seen + 1))
     [ "$prune_seen" -le "$prune_drop" ] || break
     rm -rf "$prune_entry" || printf '  ⚠️  旧 Skill 备份清理失败: %s\n' "$prune_entry" >&2

scripts/install-skills.sh

@@ -86,12 +86,34 @@ backup_and_remove_skill_dir() {
 # Only safe to call once every backup manifest of this run has been consumed,
 # because a single transaction can span more than one timestamp.
 DWS_SKILL_BACKUP_KEEP=5
+
+# is_skill_backup_stamp accepts only directory names DWS itself writes: UTC
+# YYYYmmdd-HHMMSS, with an optional -N collision suffix. Any other entry in
+# the backup root is foreign (user data, unrelated tooling) and is preserved
+# so pruning can never remove a directory it cannot prove DWS created.
+is_skill_backup_stamp() {
+  case "$1" in
+    [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]-[0-9][0-9][0-9][0-9][0-9][0-9])
+      return 0 ;;
+    [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]-[0-9][0-9][0-9][0-9][0-9][0-9]-*)
+      # base stamp is YYYYMMDD-HHMMSS (15 chars) + suffix dash (16th); strip
+      # those 16 chars and require the remainder to be all digits.
+      _isbs_suffix="${1#????????????????}"
+      case "$_isbs_suffix" in
+        ""|*[!0-9]*) return 1 ;;
+      esac
+      return 0 ;;
+  esac
+  return 1
+}
+
 prune_skill_backups() {
   _psb_root="${HOME}/.dws/skill-backups"
   [ -d "$_psb_root" ] || return 0
   _psb_total=0
   for _psb_entry in "$_psb_root"/*; do
     [ -d "$_psb_entry" ] || continue
+    is_skill_backup_stamp "${_psb_entry##*/}" || continue
     _psb_total=$((_psb_total + 1))
   done
   [ "$_psb_total" -gt "$DWS_SKILL_BACKUP_KEEP" ] || return 0
@@ -99,6 +121,7 @@ prune_skill_backups() {
   _psb_seen=0
   for _psb_entry in "$_psb_root"/*; do
     [ -d "$_psb_entry" ] || continue
+    is_skill_backup_stamp "${_psb_entry##*/}" || continue
     _psb_seen=$((_psb_seen + 1))
     [ "$_psb_seen" -le "$_psb_drop" ] || break
     rm -rf "$_psb_entry" || printf '  ⚠️  旧 Skill 备份清理失败: %s\n' "$_psb_entry"

scripts/install.ps1

@@ -744,7 +744,11 @@ $script:SkillBackupRootsThisRun = [System.Collections.Generic.HashSet[string]]::
 function Remove-OldSkillBackups {
     $root = Join-Path $HOME ".dws\skill-backups"
     if (!(Test-Path -LiteralPath $root -PathType Container)) { return }
+    # Only directories whose names match the DWS backup stamp format (UTC
+    # yyyyMMdd-HHmmss, optional -N collision suffix) are candidates; any
+    # other entry is foreign data and is preserved.
     $dirs = @(Get-ChildItem -LiteralPath $root -Directory -Force -ErrorAction SilentlyContinue |
+        Where-Object { $_.Name -match '^[0-9]{8}-[0-9]{6}(-[0-9]+)?$' } |
         Sort-Object -Property Name)
     $excess = $dirs.Count - $SkillBackupKeep
     foreach ($dir in $dirs) {

scripts/install.sh

@@ -104,12 +104,34 @@ backup_and_remove_skill_dir() {
 # Only safe to call once every backup manifest of this run has been consumed,
 # because a single transaction can span more than one timestamp.
 DWS_SKILL_BACKUP_KEEP=5
+
+# is_skill_backup_stamp accepts only directory names DWS itself writes: UTC
+# YYYYmmdd-HHMMSS, with an optional -N collision suffix. Any other entry in
+# the backup root is foreign (user data, unrelated tooling) and is preserved
+# so pruning can never remove a directory it cannot prove DWS created.
+is_skill_backup_stamp() {
+  case "$1" in
+    [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]-[0-9][0-9][0-9][0-9][0-9][0-9])
+      return 0 ;;
+    [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]-[0-9][0-9][0-9][0-9][0-9][0-9]-*)
+      # base stamp is YYYYMMDD-HHMMSS (15 chars) + suffix dash (16th); strip
+      # those 16 chars and require the remainder to be all digits.
+      _isbs_suffix="${1#????????????????}"
+      case "$_isbs_suffix" in
+        ""|*[!0-9]*) return 1 ;;
+      esac
+      return 0 ;;
+  esac
+  return 1
+}
+
 prune_skill_backups() {
   _psb_root="${HOME}/.dws/skill-backups"
   [ -d "$_psb_root" ] || return 0
   _psb_total=0
   for _psb_entry in "$_psb_root"/*; do
     [ -d "$_psb_entry" ] || continue
+    is_skill_backup_stamp "${_psb_entry##*/}" || continue
     _psb_total=$((_psb_total + 1))
   done
   [ "$_psb_total" -gt "$DWS_SKILL_BACKUP_KEEP" ] || return 0
@@ -117,6 +139,7 @@ prune_skill_backups() {
   _psb_seen=0
   for _psb_entry in "$_psb_root"/*; do
     [ -d "$_psb_entry" ] || continue
+    is_skill_backup_stamp "${_psb_entry##*/}" || continue
     _psb_seen=$((_psb_seen + 1))
     [ "$_psb_seen" -le "$_psb_drop" ] || break
     rm -rf "$_psb_entry" || say "  ⚠️  旧 Skill 备份清理失败: $_psb_entry"

test/scripts/install_js_smoke.mjs

@@ -44,9 +44,10 @@
  *                             guard, exercised by swapping process.platform
  *                             instead of requiring a Windows host.
  *  14. backup retention     — ~/.dws/skill-backups keeps the newest 5 stamps.
- *  15. multi publish failure — restores the complete previous Skill set.
- *  16. multi backup failure  — restores every earlier successful backup.
- *  17. mono transaction failure — restores every managed multi Skill after
+ *  15. unknown preservation — prune never removes non-DWS directories in skill-backups.
+ *  16. multi publish failure — restores the complete previous Skill set.
+ *  17. multi backup failure  — restores every earlier successful backup.
+ *  18. mono transaction failure — restores every managed multi Skill after
  *                                 later backup or mono publish failure.
  *
  * Requirements: unix host with tar/zip/unzip on PATH (the same tools
@@ -80,6 +81,8 @@ const {
   UPSTREAM_AGENTS,
   resolvedAgentTargets,
   agentTargetDetected,
+  isSkillBackupStamp,
+  pruneSkillBackups,
   backupAndRemoveSkillDir,
   movePathRecoverablySync,
   publishCacheAtomically,
@@ -1003,6 +1006,49 @@ scenario("skill backups stay bounded to the newest five stamps", () => {
   }
 });
 
+scenario("prune preserves unknown directories in skill-backups", () => {
+  const tmp = fs.mkdtempSync(path.join(os.tmpdir(), "dws-installjs-prune-unknown-"));
+  const home = path.join(tmp, "home");
+  const backupRoot = path.join(home, ".dws", "skill-backups");
+  try {
+    for (const stamp of [
+      "20260101-000001", "20260101-000002", "20260101-000003",
+      "20260101-000004", "20260101-000005", "20260101-000006", "20260101-000007",
+    ]) {
+      writeFile(path.join(backupRoot, stamp, "placeholder", "SKILL.md"), `${stamp}\n`);
+    }
+    const unknowns = [
+      "user-personal-backup",
+      "20260101-00000",      // too few digits in the time part
+      "20260101-000000-abc", // non-numeric suffix
+      "notes",
+      "20260101",            // missing time portion
+    ];
+    for (const name of unknowns) {
+      writeFile(path.join(backupRoot, name, "marker.txt"), `unknown:${name}\n`);
+    }
+
+    pruneSkillBackups(home);
+
+    const remaining = fs.readdirSync(backupRoot).sort();
+    const stamped = remaining.filter((n) => isSkillBackupStamp(n));
+    assert.equal(stamped.length, 5, `stamped backups = ${stamped.length}, want 5`);
+    assert.ok(!stamped.includes("20260101-000001"), "oldest stamps pruned first");
+    assert.ok(!stamped.includes("20260101-000002"), "second-oldest pruned");
+    assert.ok(stamped.includes("20260101-000005"), "newest kept stamps retained");
+    for (const name of unknowns) {
+      assert.ok(remaining.includes(name), `unknown directory ${name} must survive pruning`);
+      assert.equal(
+        fs.readFileSync(path.join(backupRoot, name, "marker.txt"), "utf8"),
+        `unknown:${name}\n`,
+        `unknown directory ${name} contents must be intact`,
+      );
+    }
+  } finally {
+    fs.rmSync(tmp, { recursive: true, force: true });
+  }
+});
+
 scenario("multi set publish failure restores the complete previous set", () => {
   const tmp = fs.mkdtempSync(path.join(os.tmpdir(), "dws-installjs-multi-set-"));
   const home = path.join(tmp, "home");