Implement technical SEO baseline for marketing site

[diese-tech]

Summary

Implement the missing technical SEO assets for the public marketing site. The landing page already includes Next.js Metadata API support (title, description, Open Graph, Twitter, canonical, and robots metadata), but several crawl and structured data assets are still missing.

Current State

Already implemented

• Canonical metadata
• Open Graph metadata
• Twitter cards
• Page metadata
• Privacy Policy
• Terms of Service

Missing

• robots.txt
• sitemap.xml
• JSON-LD structured data
• llms.txt
• ai.txt (optional)
• Cookie Policy (if applicable)

Tasks

1. Add robots.txt

• Implement src/app/robots.ts
• Allow all crawlers
• Reference the production sitemap

2. Add sitemap.xml

• Implement src/app/sitemap.ts
• Include all public marketing pages
• Exclude authenticated application routes

3. Add JSON-LD

Inject structured data from the root layout.

Include:

• Organization
• SoftwareApplication
• WebSite

Render via application/ld+json.

4. Add llms.txt

Create public/llms.txt describing:

• Product
• Target audience
• Primary features
• Canonical website
• Documentation (future)
• Contact (future)

5. Add ai.txt

Create public/ai.txt mirroring the information in llms.txt.

6. Cookie Policy

If analytics or marketing cookies are used, add a Cookie Policy page and footer link. Otherwise, document why one is unnecessary.

Acceptance Criteria

• /robots.txt resolves
• /sitemap.xml resolves
• JSON-LD validates in Google's Rich Results Test
• SEO Loupe no longer reports missing robots, sitemap, or structured data
• llms.txt resolves
• No visual regressions to the marketing site