Improve docs search with fuzzy matching and smart navigation

[satyansh2004]

This PR improves the docs search UX by replacing exact string matching with
Fuse.js-based fuzzy search.

• Supports typo-tolerant and similar-word matching
• Preserves existing text-fragment navigation for exact matches
• Falls back to nearest page/section for fuzzy matches
• No backend changes; minimal client-side impact

Fixes #2362

[CLAassistant]

All committers have signed the CLA.

[reynaldichernando]

hi @satyansh2004 , thank you for the PR
let me test this thoroughly first, since its a major change

[satyansh2004]

Thanks for reviewing this. Happy to make any changes if you find issues during testing.

[reynaldichernando]

hi @satyansh2004 , thank you for the PR, i have done testing, and found some issues:

• text fragment matching broken
  • the change removed our existing custom text fragment matching logic, where it allows it to detect position of the keyword if there are duplicates around
  • we are using prefix and suffix to detect this
• it doesn't jump to the nearest subheading with fuzzy search
• autocomplete is broken
  • it doesn't show either the fuzzy match or the exact match highlight

let me know if you need any clarification for these

[satyansh2004]

ok, I will resolve these issues asyou described here as soon as possible