docs(fleet): add PegaProx, iVentoy remastering procedures, update admin cheat sheet
- fleet/admin-cheat-sheet.md: Added PegaProx section, updated MK33/MK34/MK39
statuses to Online (PVE), added iVentoy remastering notes, iVentoy Pro
upgrade pending marker.
- procedures/pega-prox-deploy.md: New procedure for deploying PegaProx on
Docker Swarm (host mode, CSRF, API gotchas).
- procedures/iventoy-remaster-procedure.md: New procedure for remastering
Proxmox ISOs with embedded answer URLs and locked gfxmode.
- changelog/2026-05-31-pxe-pegaprox-deployment.md: Changelog entry for todays
fleet work.
- 04-service-catalog.md: Added PegaProx to Management / Dashboard section.
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