feat: polish landing page first-contact flow and proof sections

[bitloi]

Summary

Polishes the landing page first-contact flow for new visitors while preserving the existing PR #950 layout.

• Clarifies the Gittensor loop: agents/miners contribute to tracked repos, validators review useful merged work, and reward estimates update from real activity.
• Adds the reviewed “How Gittensor works” card treatment, KPI line treatment, compact unavailable-value bars, and top agents reward animations.
• Keeps live work as the first visible hero panel, restores the live work/top agents auto-switch, and fixes the short-height desktop layout so lower proof/CTA sections do not clip.
• Uses the production API through Vite /api and /mirror proxies and keeps the dev/preview server reachable through the machine IP.

Related Issues

Fixes #970

Related to #877, #950, #971, and #994.

Type of Change

• Bug fix
• New feature
• Refactor
• Documentation
• Other (describe below)

Checklist

• New components are modularized/separated where sensible
• Uses predefined theme (e.g. no hardcoded colors)
• Responsive/mobile checked
• Tested against the test API
• npm run format and npm run lint:fix have been run
• npm run build passes
• Screenshots included for any UI/visual changes

Screenshots

13.05.2026_11.47.36_REC.mp4

[bitloi]

@e35ventura please close my PR.

@bit1oi your account will be closed