Fix esbuild Dependabot security alert with npm override

[aivascu]

Summary

• Add an npm override to pin esbuild to >=0.28.1, resolving GHSA-g7r4-m6w7-qqqr.
• Remove the nested esbuild 0.27.7 copy pulled in by fontless (@nuxt/fonts), which Dependabot could not auto-update without downgrading @nuxt/fonts.
• npm audit now reports 0 vulnerabilities.

Test plan

• npm install in site/
• npm run generate (static site build succeeds)
• CI passes
• Dependabot alert #65 closes after merge