Add fuzzy search language picker with rich labels

- Replace dropdown with searchable combobox for language selection
- Rich label shows language name, ID, and category tag when not focused
- Click to enter search mode with empty input, type to filter
- Fuzzy matching against language name, ID, and tag
- Keyboard navigation (arrows, enter, escape)
- Highlight matched characters in search results
- Category tag badges (programming, markup, config, data, shell, query)
- Add language metadata for all 70+ supported languages
- Add code examples for many languages (F#, PHP, VB, Haskell, Ruby, Scala, etc.)
- Switch compression label from "brotli" to "gzip" to match actual compression

Author: fasterthanlime