refine post-install and hardware GPU docs, Monitor UX and CLI styling

- rewrite the 15 post-install pages and the 3 hardware GPU pages so they reflect the current scripts (reversibility, tracked-tool counts, kernel parameters, per-tool commands, Alpine LXC propagation flow)
- migrate the legacy step-badge helper on post-install/optional and create-vm/synology to the canonical pill component, with the stepLabel key added in each locale
- fix rich-text i18n calls missing helpers across network, automated, optional, security, customization and the post-install landing pages, and escape the `<iface>` placeholder in automated so intl no longer parses it as a tag
- remove the mouse-follow blue overlay from the docs landing layout
- reposition the App-tab Edit button and stack the Search and Register controls vertically on mobile
- move the Bulk update Configure/Edit control into the section header so it behaves the same on desktop and mobile
- show a spinner during the final autoremove/autoclean pass of update-pve-safe so the cleanup step reads as active instead of silent
- restyle the shell spinner and msg_info in a distinctive purple and drop the unused msg_lang duplicate
- add a web-docs i18n build script and its CI workflow, plus tests for the pushover notification channel

web/messages/en/docs/monitor/dashboard/vms-lxcs-updates.json

@@ -25,6 +25,7 @@
   "mechanisms": {
     "heading": "How an update method is selected",
     "lead": "The integrated Proxmox VE Helper-Scripts path follows the official <helper>update-apps mechanism</helper>. Other install types use the matching package, Docker or custom path.",
+    "officialReference": "Official reference: the <helper>Proxmox VE Helper-Scripts update-apps documentation</helper> covers interactive and unattended modes, backups, dry runs, temporary build resources, logs and exit codes.",
     "colSource": "Source",
     "colAction": "Displayed action",
     "colNotes": "What runs",