Disable publishing option for fullstack-stateful-app artifacts

[StpMax]

Description

Block publishing of fullstack-stateful-app artifacts. A stateful fullstack app
keeps server-side state the static publish pipeline can't carry, so a published
copy would be broken/misleading.

How

• Add a shared publishBlockedReason(a) predicate in artifactKinds.js (single
  source of truth, keyed on artifact type).
• Render the Publish control visible but disabled with an explanatory tooltip
  (not hidden), across all five publish surfaces:
  • Artifact viewer — main button
  • Artifact viewer — kebab menu (ActionsPopover)
  • Artifacts page — list-mode row menu (RowMenu)
  • Artifacts page — grid-mode card menu (HoverMenu)
  • Working-folder rail toggle
• Guard the three publish handlers (onPublish, handlePublish,
  onTogglePublish) as defense-in-depth.
• Leave Unpublish untouched; only the publish direction is blocked.

Screenshots

Type of change

Please delete options that are not relevant.

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ⚡ New feature (non-breaking change which adds functionality)
• 🚨 Hotfix (non-breaking change which fixes an issue)
• 📢 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📄 This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have checked my code and corrected any misspellings