[FE-23] Build LoadingSkeleton component

[mftee]

Problem

Pages that load data asynchronously flash an empty white screen while the request is in flight. This creates a jarring experience and gives no indication to the user that content is loading.

Proposed Solution

Create a LoadingSkeleton component inside frontend/module/components/loading-skeleton/ that renders animated placeholder blocks matching the layout of common page sections.

Acceptance Criteria

• Exports a base Skeleton component that renders an animated shimmer block with configurable width, height, and borderRadius props
• Exports a DocumentCardSkeleton variant that matches the layout of a document list row
• Exports a StatCardSkeleton variant that matches the layout of a dashboard stat card
• Exports a TableRowSkeleton variant with configurable columnCount prop for table loading states
• Animation is a left-to-right shimmer effect using CSS animation (no JavaScript animation libraries required)
• All skeleton variants respect the prefers-reduced-motion media query and show a static grey block instead of the animated shimmer
• All component files live inside frontend/module/components/loading-skeleton/

[NteinPrecious]

@NteinPrecious has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

https://www.drips.network/wave/stellar/issues/d3df4daa-0d29-4187-ae46-dea1a5c3a0da?filters=eyJyZXBvSWQiOiJjY2Y0YjMxNy0wYmMyLTQ5YmItYTA3Mi02NGE4YzZmMmZhNmMiLCJzdGF0ZSI6Im9wZW4ifQ%3D%3D&sortBy=createdAt

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[drips-wave]

Congratulations, @NteinPrecious! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @NteinPrecious: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

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[drips-wave]

This issue has been completed by @NteinPrecious as part of the Stellar Wave Program's 5th Wave 🥳

😎 @NteinPrecious: You earned 200 Points for completing this issue! After the current Wave ends, you'll be eligible for a percentage of the Wave's reward pool based on the percentage of total points you've earned. Learn more here. You can also Leave a review to share your experience working on this issue.

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