fix(ui): persist folder upload input across page refresh

[MunemHashmi]

Summary

Fixes #58

After a page refresh on /upload, the file input lost its webkitdirectory attribute and switched from folder selection mode to individual file mode. This made it impossible to upload multi-file skills via the browser after refreshing.

Root cause

The webkitdirectory and directory attributes were set via:

1. Non-standard JSX props (@ts-expect-error) — React may strip these during hydration
2. A useEffect([], ...) fallback — doesn't re-fire when React hydrates (rather than fresh-mounts) the component after a page refresh

Fix

Replaced both approaches with a ref callback that imperatively sets webkitdirectory and directory every time the input element is attached to the DOM. This is reliable across initial render, hydration, and re-renders.

Test plan

• bun run test -- src/__tests__/upload.route.test.tsx — 8/8 pass (existing test marks the input for folder uploads still passes)
• bun run lint — 0 warnings, 0 errors

[vercel]

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[greptile-apps]

Greptile Summary

Fixes folder upload input losing webkitdirectory attribute after page refresh by replacing JSX props and useEffect with a ref callback that imperatively sets attributes on every DOM attachment.

• Removed non-standard JSX attributes (webkitdirectory, directory) with @ts-expect-error
• Removed useEffect([], ...) that only fired on initial mount, not hydration
• Introduced setFileInputRef callback that sets attributes via setAttribute whenever the input is attached to the DOM
• Ensures folder selection mode persists across initial render, hydration, and re-renders
• All tests pass, no lint errors

Confidence Score: 5/5

• This PR is safe to merge with no risk
• The fix correctly addresses the root cause using the recommended React pattern (ref callbacks) for setting non-standard DOM attributes. Tests pass, no lint errors, and the approach is both sound and well-documented with clear comments.
• No files require special attention

_{Last reviewed commit: 55100fc}