Feat/pool distribution bar a11y

[Devadakene]

Closes #143
Description
This PR enhances the accessibility and interactivity of the PoolDistributionBar component by making each legend entry focusable and visually highlighting the corresponding SVG segment on hover or focus.

Changes
Accessibility Upgrade: Wrapped the static legend items (

) with keyboard-focusable elements styled to blend in seamlessly.
Visual Feedback: Added a stateful highlightedAsset hook to detect which legend entry is hovered/focused.
Segment Highlighting: SVG elements now visually dim (opacity reduces to 0.4) when another asset is active, keeping the highlighted segment fully visible.
DOM Metadata: Added data-highlighted="true"|"false" attributes to the SVG elements to aid testing and potential CSS target hook.
Coverage & Tests: Extended
PoolDistributionBar.test.tsx
with test assertions checking:
Button elements exist in the legend for focusability.
Hovering or focusing legend entries correctly updates the visual representation (opacity, custom attributes).
Verification
Ran the vitest test suite successfully:

bash

bun run vitest run src/components/PoolDistributionBar.test.tsx
Result: All tests passed.

[Jagadeeshftw]

Thanks for this — after resolving the merge, this ends up fully redundant with main: both the api.ts timeout/AbortSignal composition and the PoolDistributionBar hover-highlight accessibility feature already landed via #380 (that branch carried this same content). Zero net diff left, so closing as already covered rather than merging a duplicate.