test: prefer auto-cleaning temp dir helper (#93209)

Summary:
- The branch adds `useAutoCleanupTempDirTracker()`, broadens the temp-dir warning reporter to flag new manual helper imports/usages, updates docs, and migrates two script tests to the new helper.
- PR surface: Tests +301, Docs +1, Other +248. Total +550 across 8 files.
- Reproducibility: not applicable. this is test/tooling cleanup, and the changed behavior is exercised through helper/reporter tests and CI evidence rather than a user reproduction path.

Automerge notes:
- PR branch already contained follow-up commit before automerge: test: harden temp dir helper guard
- PR branch already contained follow-up commit before automerge: test: clarify auto cleanup temp dir helper name
- PR branch already contained follow-up commit before automerge: test: cover existing mkdtemp temp dir forms
- PR branch already contained follow-up commit before automerge: test: read staged temp helper source from index

Validation:
- ClawSweeper review passed for head 1fdd7d2a9a.
- Required merge gates passed before the squash merge.

Prepared head SHA: 1fdd7d2a9a
Review: https://github.com/openclaw/openclaw/pull/93209#issuecomment-4705653665

Co-authored-by: Mason Huang <masonxhuang@tencent.com>
Approved-by: hxy91819

src/scripts/test-projects.test.ts

@@ -913,6 +913,7 @@ describe("test-projects args", () => {
           "test/scripts/native-app-i18n.test.ts",
           "test/scripts/onboard-config-fixtures.test.ts",
           "test/scripts/parallels-lib-helpers.test.ts",
+          "test/scripts/parallels-package-log-progress-extract.test.ts",
           "test/scripts/parallels-smoke-model.test.ts",
           "test/scripts/plugin-package-dependencies.test.ts",
           "test/scripts/plugins-assertions.test.ts",
@@ -921,6 +922,7 @@ describe("test-projects args", () => {
           "test/scripts/release-preflight.test.ts",
           "test/scripts/render-maturity-docs.test.ts",
           "test/scripts/report-test-temp-creations.test.ts",
+          "test/scripts/runtime-postbuild-stamp.test.ts",
           "test/scripts/test-install-sh-docker.test.ts",
           "test/scripts/test-projects.test.ts",
           "test/test-env.test.ts",