[Website][Launch] SEO and performance baseline

[web2solutions]

Parent epic: #124
Story points: 5

Objective
Add SEO, discoverability, and performance baseline for launch readiness.

Scope

• Metadata and social cards.
• Sitemap and robots rules.
• Structured data where relevant.
• Performance checks for Core Web Vitals baseline.

Acceptance Criteria

• SEO metadata present on key pages.
• Sitemap generated.
• Performance baseline documented and validated.

[web2solutions]

Progress update (implementation in workspace):

• Added sitemap generation route:
  • apps/jumentix-website/app/sitemap.ts
• Added robots rules route:
  • apps/jumentix-website/app/robots.ts
• Enhanced global metadata for social/SEO previews:
  • apps/jumentix-website/config/index.ts (OpenGraph + Twitter card image metadata)
• Added baseline documentation:
  • apps/jumentix-website/documentation/SEO-AND-PERFORMANCE-BASELINE.md
• Linked SEO/performance doc from website README.

Traceability status:

• PR: pending (will be attached before closure)
• Commit evidence: pending (will be attached before closure)