docs: add hero image to README

[livlign]

Adds a hero image at the top of the README, mirroring the veloxdb.dev visual identity (pure black, zinc-800 chrome, Geist Sans/Mono, white→zinc gradient title, pink accent).

The image showcases the SQL workspace — Monaco-style editor, schema sidebar, run bar with live stats, and the virtual-scrolled results grid — over the existing tagline "PostgreSQL, unleashed on your desktop."

What changed

• assets/hero.png — 1200×675 @2x, 395 KB
• README.md — embedded under the badges block, with descriptive alt text that mirrors the on-image content for screen-reader users

Notes

• No volatile stats (stars/version/release dates) baked into the image, so it won't drift against the dynamic badges above it.
• Image-only PR — no source/sidecar files added.

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Generated with repo-visuals.

[abeni16]

I loved this, but unfortunately, that is not my logo. Here is my logo.

[livlign]

Thanks! I have updated with the correct logo.