Fix duplicate About link and restore complete web CV

[sabujcb]

Fixes

• remove the second About navigation item by disabling the redundant explicit homepage nav entry
• keep the theme's built-in About/home link as the single navigation item
• replace the incompatible legacy CV renderer with a responsive portfolio-native CV page
• restore visible Skills, Languages, and Interests content
• retain Profile, Experience, Education, Selected Projects, PDF download, GitHub, and LinkedIn
• preserve the redacted contact/location policy

Root causes

• the theme adds the homepage/About link automatically, while _pages/about.md also had nav: true
• the RenderCV v2 data uses label and details, but the legacy web layout expected name and keywords, producing blank rows

Validation

• Prettier formatting
• YAML/front-matter parsing
• explicit assertion that About has nav: false
• non-empty Skills, Languages, and Interests checks
• Liquid loop/condition balance checks
• git diff --check
• final Jekyll build delegated to GitHub Actions