feat(explorer): take down / unpublish selected item (#4533)

[natechadwick-intsof]

Summary

Explorer Take Down (unpublish) for a selected page or asset on spa.jsp?entry=explorer. Peer of Publish Now (itemPublish + actionDispatch). Uses existing sitemanage GET /services/sitemanage/publish/takedown/page|resource/{id} (PUT of linked pages when findLinkedItems returns any). Confirm first; HTTP 200 FORBIDDEN / BADCONFIG / NOSTAGING_SERVERS / INVALID is a failure (Server actions error), not success. Folders and non-page/asset types stay hidden.

Parent tracker: #4530. Slice 1 of Explorer publish-adjacent actions.

Does not implement stage/unstage, schedule dates, PublishingShell history, or #4472. Does not edit product-docs/8.2/developer/rest.md.

Fixes #4533

Operator: Grok: night-issue-prs (model grok-4.6)

Test plan

1. QA H2: python docker/scripts/perc-devctl.py qa-up --skip-image-build (this run: TEST_CMS_URL=http://127.0.0.1:9993).
2. qa-health with QA_CMS_HOST_PORT from qa-up → RESULT:OK HTTP 200 HEALTH:healthy.
3. qa-deploy-webui then qa-health again.
4. From modules/perc-qa-automation/frontend: npm run test:surface -- --path tests/explorer-action-dispatch.spec.js (3 passed, including Take Down FORBIDDEN).
5. npm run test:golden (2 passed).
6. Explorer: select a page/asset → Take Down visible; confirm; 403/FORBIDDEN shows error, list does not refresh as success. Folder-only selection hides Take Down.

Checklist

• Product documentation — updated product-docs/8.2/admin/content-explorer.md (Take Down row) and a short Explorer pointer on product-docs/8.2/admin/publishing.md
• Unit / module tests — itemPublish, actionDispatch, actionEnablement, ContentExplorerShell; WebUI + perc-qa-automation standalone mvnw clean install
• WebUI + Playwright — tests/explorer-action-dispatch.spec.js Take Down FORBIDDEN spec + golden smoke
• Build gates — standalone clean install on changed Maven modules (no skipTests)
• Cross-platform — N/A (no OS filesystem path I/O; URL joins use / and encodeURIComponent)

C3 evidence

• modules_built: WebUI, modules/perc-qa-automation
• build_evidence:
  • cd WebUI && ../mvnw clean install → BUILD SUCCESS; Surefire Tests run: 69, Failures: 0; Vitest Tests 4264 passed (4264)
  • cd modules/perc-qa-automation && ../../mvnw clean install → BUILD SUCCESS (No tests to run / npm ci)
• downstream_checked: none (no Java public/protected signature or final/sealed type change)

C5 UI proof

• qa-up --skip-image-build → TEST_CMS_URL=http://127.0.0.1:9993 container perc-matrix-cms-h2
• qa-health → RESULT:OK STEP:qa-health HTTP:200 HEALTH:healthy URL:http://127.0.0.1:9993/Rhythmyx/rest/mimetypes
• qa-deploy-webui → RESULT:OK; qa-health again → RESULT:OK HTTP:200 HEALTH:healthy
• Playwright: npm run test:surface -- --path tests/explorer-action-dispatch.spec.js → 3 passed (including Take Down FORBIDDEN)
• Golden: npm run test:golden → 2 passed
• console-clean: yes (spec pageerror listeners empty)
• server.log-clean: yes for takedown itself (intercepted). Catalog lookup ERROR for injected fake content id 42 (PSComponentSummary does not exist) is the same fixture as the existing Publish Now FORBIDDEN spec, not a takedown job failure.

Co-Authored by Grok Build 1.0.34 using grok-4.6 with agent night-issue-prs.

[natechadwick-intsof]

Remaining Explorer publish-adjacent slices (not in this PR): stage/unstage #4546, schedule dates #4547.

Co-Authored by Grok Build 1.0.34 using grok-4.6 with agent night-issue-prs.