Remove Software Handoff Kit from the site

[azurras]

Summary

Remove the software handoff material requested by the user:

• Delete the offer/checklist/example template and free worksheet.
• Remove Tools navigation and sitemap entries.
• Retire both exact former GET URLs with empty410 Gone, no-store/noindex, no attachment. Keep mutation denial and existing neighboring-page404 behavior.
• Update owning docs and native regressions. Website Monitor unchanged.

Verification

• New route/resource/sitemap/nav regressions observed fail before removal.
• View/Sitemap tests pass; corrected security fixture (existing public unknown-page fallback404), SecurityConfigTest passes.
• JS380/380, nav syntax and bootJar passed.
• Packaged native Windows candidate18092 on owned27031/test: anonymous retiredGET410empty/noattachment/no-store/noindex, POST403, neighbors404, sitemap/nav nooffer, monitor/readiness200.
• JAR contains no handoff offer/worksheet resources; owned candidate/Mongo stopped, production untouched.
• Independent final immutable patch review E38EB6B6B2A27FC0FD23F53AEBC750914A378E07FE72C46B9B6B8CEF1243F697: no blockers.
• Builder plan/candidate runtime report published. Full platform CI required before merge; supported automatic deploy and public acceptance afterward.

No elevated access, production test records or browser permission retries. Separate local product archives and historical records remain outside site-removal scope.