fix: PublishingShell item takedown HTTP status mapping (#4742)

[natechadwick-intsof]

Summary

Parent: #4531. Slice #4742.

Publishing site-workspace Remove From Site already unpublishes a page or asset (it does not delete the CMS content item). This change maps HTTP 400, 403, 404, and 409 on that panel to operator errors instead of success, and documents that behavior.

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

Test plan

• Vitest ItemTakedownPanel and takedownSelectedItem (takedown URL, not delete)
• Playwright tests/publishing/itemTakedown.spec.js on H2 QA (3 passed), including 400/403/404/409
• Human: confirm a real published item can be taken down and still opens in Explorer

Product documentation

• Updated product-docs/8.2/admin/publishing.md (take down does not delete the item; HTTP 400/403/404/409)

Maven / C3

• modules_built: WebUI, modules/perc-qa-automation
• cd WebUI && rtk mvn clean install — BUILD SUCCESS. Java Tests run: 69, Failures: 0. Vitest: Test Files 519 passed, Tests 4808 passed.
• cd modules/perc-qa-automation && rtk mvn clean install — BUILD SUCCESS. No tests to run (Playwright is opt-in).
• downstream_checked: none (no public Java signature change)

C5 UI proof

• python3 docker/scripts/perc-devctl.py qa-up — TEST_CMS_URL=http://127.0.0.1:9993 (freeport; do not hardcode)
• qa-health RESULT:OK HEALTH:healthy
• qa-deploy-webui then qa-health again RESULT:OK
• npm run test:surface -- --path tests/publishing/itemTakedown.spec.js — 3 passed
• console-clean=yes (pageerror listeners empty)
• server.log-clean=yes (no new ERROR/FATAL in the test window)
• qa-down RESULT:OK

Fixes #4742

Pre-push local code review

Erlang review — PR #4755

Scope

• Persona: erlang 0.1.1
• Persona source: /home/nate/.local/share/mkd/agents/erlang
• Status: mkd-code-review 0.1.18, pack percussion, --gate advisory, --git-base origin/main
• PR: fix: PublishingShell item takedown HTTP status mapping (#4742) #4755
• Base: origin/main
• Head: 7adb07b
• Files analyzed: 5
• Reviewer disposition: approve. Machine gate: 0 findings. Manual read of ItemTakedownPanel status mapping (400/404/409), Vitest, and Playwright agrees: failures stay on the error panel and takedown does not call delete. No rule-file diffs.
• Recommendation: approve. May merge: yes, when required checks are green.

CLI stdout (mkd-code-review analyze --format markdown)

Summary

Machine analysis found 0 finding(s), 0 bug(s).

Scope

• Base: origin/main
• Head: HEAD
• Files: 5 analyzed
• Persona: erlang 0.1.1
• Persona source: /home/nate/.local/share/mkd/agents/erlang

Recommendation

approve

Gate

• Blocking bugs: 0
• May commit/push: yes

Issues

No issues.

[natechadwick-intsof]

LGTM. Independent Erlang review (mkd-code-review 0.1.18, persona erlang 0.1.1, gate advisory). No in-diff bugs. GitHub rejected same-login APPROVE; this comment is the LGTM. Full CLI report is in the PR body under Pre-push local code review and in docs/ai-generated/code-reviews/pr-4755-erlang.md.

Co-Authored by Grok Build 1.0.40 using grok-4.6 with agent night-issue-prs-erlang.