feat: Improve library search matching

[falfaddaghi]

Summary

Improves the Library panel search so it handles more natural matching beyond simple lowercase substring checks. Search now supports normalized matching across item metadata and nested workflow/node content, with relevance ranking for better result ordering.

Checklist

• Added a reusable library search helper with normalization, token matching, acronym matching, fuzzy typo tolerance, and ranking
• Updated the Library panel controller to use ranked search for saved workflows, marketplace workflows, and library items
• Expanded searchable fields to include descriptions, category/type, marketplace/plugin names, and nested workflow/node payload strings
• Added regression tests for normalization, typo tolerance, acronym/subsequence matching, ranking, and nested string extraction

Key changes

• Added src/lib/library-search.ts
• Added src/lib/__tests__/library-search.test.ts
• Updated src/components/workflow/library-panel/use-library-panel-controller.ts

Validation

• bun test src/lib/__tests__/library-search.test.ts
• Targeted TypeScript check for changed files
• Targeted ESLint for changed files