fix/issue-970-landing-page-polish

[CaptainTimon]

Summary

Polishes the landing page first-contact flow so new visitors can understand the Gittensor loop faster: miners join, work on tracked repositories, validators verify useful merged work, and reward estimates come from live contribution data.

What changed

• Reworked the hero layout and proof stats for better large-screen fit, clearer spacing, and less overlap risk on shorter desktop viewports.
• Expanded the "How it works" section with clearer Join / Build / Reward steps, icons, result callouts, and stronger visual hierarchy.
• Improved live proof and top-miner presentation with animated reward bars, count-up reward values, loading skeletons, and calmer panel switching.
• Tuned maintainer/miner onboarding cards and tab placement so lower landing-page sections remain readable across responsive breakpoints.
• Added configurable Vite host/proxy support through VITE_ALLOWED_HOSTS, VITE_DEV_ORIGIN, and optional VITE_USE_PROD_API_PROXY for production API/mirror proxying in dev or preview.

Testing

• Not run; PR description update only.

Closes #970

[bitloi]

@CaptainTimon You have to improve your fork speed.

[anderdc]

Duplicate of #1089 which is better scoped/implemented. Closing.