Lead the site with review receipts

[onatozmenn]

The home page currently leads with an abstract language rule while the product's clearest adoption surface, reviewing an agent patch for new authority, lives one page down.

This redesign makes that value the first viewport:

• names the concrete job: new authority, weaker guarantees, and runtime checks
• shows a compact deed review receipt beside the offer
• keeps the existing mono/bracket visual language instead of introducing a generic SaaS theme
• explains the path from signature to receipt to CI
• keeps mobile navigation on one horizontal row
• updates the landing metadata and license copy

The compact receipt is not an unverified sample. tools/check.mjs now asks the pinned v0.2.13 WASM compiler for the existing review fixture and holds the landing authority, tier change, and blocked result against that answer.

Validation:

• node tools/check.mjs: 73 files, all links resolve, v0.2.13 loads and answers about all 29 examples
• break verification: changing the landing authority to Store.read fails with index.html: does not show the review demo authority Store.write
• Playwright at 1440x900, 1024x768, 390x844, and 320x568 in light/dark modes
• no horizontal overflow, element overlap, failed requests, or console errors
• the receipt and a hint of the next section remain visible in every tested first viewport