Make Swift and Rust clickable in the landing page SDK animation

[devin-ai-integration]

Summary

The Swift and Rust tabs in the landing page SDK card render grey and do nothing on hover/click. They are static artwork inside the compiled sdk-rive.riv (hosted on the Webflow CDN): its state machine only defines TypeScript, Python, GO, Java, NET, PHP and Ruby, so there is nothing in this repo to enable. Fixing it properly requires re-authoring the Rive file.

Workaround: two real anchors are layered over those two tab positions in welcome.mdx, styled to be indistinguishable from the neighboring tabs (same icon size, JetBrains Mono label, matching #fcfcfd / #111113 panel background so the grey artwork underneath is fully covered) and pointing at /sdks/generators/{swift,rust}/quickstart.

Geometry is expressed as percentages of the 369x93 artboard, with container-type: inline-size on .rive-container so icon/label sizes scale in cqw and stay aligned at any width:

.rive-tab { position: absolute; top: 34.34%; height: 28.6%; width: 10.46%; }
.rive-tab-swift { left: 76.53%; }  /* tab pitch is 10.46% of the artboard */
.rive-tab-rust  { left: 86.99%; }

That only holds while the container box matches the artboard ratio. rive-animation.js set container.style.height = width / aspectRatio once at load and never again, so after a window resize the artwork letterboxed inside a stale-height container. The height computation is now a syncContainerHeight() closure called from the existing resize handler as well:

const windowResizeHandler = () => {
    syncContainerHeight();
    r.resizeDrawingSurfaceToCanvas();
};

Verified against the live page with the final CSS/markup injected, in light and dark mode and at a narrowed container width; the overlay tabs line up with the Rive-rendered ones and the existing hover interactions for the other languages are untouched.

Link to Devin session: https://app.devin.ai/sessions/3f1fa02d46d94431b1331d3d9ae97933

[devin-ai-integration]

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[github-actions]

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