Add unified data state UI system for loading skeletons and empty states across list pages

[Chucks1093]

Summary

List and data pages currently handle loading and empty states independently, producing inconsistent UI and repeated logic. A unified approach should standardise both concerns: skeleton placeholders during fetching and empty state components when queries settle with zero results.

Scope

• Add a CreatorCardSkeleton component matching the real card dimensions with animated pulse on avatar, name, price, and holder count placeholders
• Add an EmptyState component accepting a message and an optional CTA — used on holdings, creator list, and any future list page
• Wire the skeleton into creator list and holdings pages during isLoading
• Wire the empty state into holdings when the query settles with zero results; link the CTA to the creator discovery page
• Skeletons and empty states must not appear simultaneously — skeleton only during loading, empty state only after a settled empty response

Acceptance Criteria

• Skeleton matches real card layout; animated pulse on all placeholder regions
• Skeleton replaced by real card on data arrival with no layout shift
• Empty state only renders after query settles with zero results
• Empty state CTA navigates to creator discovery
• Both components used consistently on holdings and creator list pages

ETA: 12 hours

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Coordinate on Telegram

[prissca]

i will love to work on this issue

[grantfox-oss]

🦊 GrantFox — @prissca has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #545)
2. Your PR will be reviewed by the accesslayerorg maintainers

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