[Spinner] Fix duplicate CSS display and document animation timing

[ravisuhag]

Summary

Spinner is a custom loading indicator with shimmer animation. Has a conflicting accessibility pattern and minor CSS issues.

Improvements

3. Fix duplicate CSS display property

.spinner has both display: inline-block and display: flex. The flex overrides, making inline-block unnecessary.

4. Document animation timing rationale

Hardcoded animation delay values (-0.15s, -0.3s, etc.) lack documentation explaining the stagger logic.

Moved to Cross-Cutting Issues

The following items have been moved to cross-cutting issues that address them across all components:

• Accessibility baseline (Accessibility baseline: aria attributes, roles, and semantic HTML #673)

Files

• packages/raystack/raystack/components/spinner/

[rohanchkrabrty]

#817