Add submission standards section to landing page

[Chenxizhe2025]

Summary

• add a new Proof that gets approved landing page section that explains the review loop behind Gibwork tasks, bounties, and services
• show concrete submission standards: public links, screenshots/files, a short rationale, and no duplicate or copy-paste submissions
• keep the change scoped to one new component plus the homepage insertion point, with no new dependencies

Why this helps the landing page

The current homepage explains that users can create or complete work, but it does not clearly show what makes work reviewable and payout-ready. This section makes the platform feel more operationally current by showing both sides of the marketplace how clear scope, verifiable proof, quality checks, and wallet payouts connect.

Verification

• npm run build passes
• git diff --check passes
• local production preview at http://localhost:3107/#proof returns 200 and includes the new section text
• Chrome desktop screenshot check: proof section renders with the checklist and four cards visible
• Chrome mobile screenshot check: section stacks cleanly at 390px width without text overlap

Task context

Submitted for the funded Gibwork task: Improve Gibwork Landing Page or Submit a GitHub Enhancement.
Task URL: https://app.gib.work/tasks/b7c2a3c9-c412-4613-9cfb-d8a5f54d14b7

[vercel]

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