Fix rtl text rendering (#21382)

Fix rtl text rendering (#21382)

* Fix Arabic RTL text rendering in web UI

- Add dir='auto' attributes to markdown containers and blocks
- Implement post-processing to add dir='auto' to all text elements
- Replace directional CSS properties with logical properties for proper RTL list alignment
- Ensure bidirectional text support for mixed Arabic/English content

* Clean up commented duplicate function

Remove the commented-out duplicate transformMdastNode function
that was left over from refactoring.

* Fix Arabic RTL text rendering in web UI

- Add dir='auto' attributes to markdown containers and blocks
- Implement post-processing to add dir='auto' to all text elements
- Replace directional CSS properties with logical properties for proper RTL list alignment
- Minor code formatting improvements

This ensures bidirectional text support for mixed Arabic/English content in the llama.cpp web UI.

* Implement rehype plugin for comprehensive RTL text support

- Add rehypeRtlSupport plugin that applies dir='auto' to all elements with children
- Replace DOMParser-based approach with efficient HAST tree processing
- Remove hardcoded element lists for better maintainability
- Ensure proper bidirectional text rendering for mixed RTL/LTR content

* Fix RTL text rendering with rehype plugin and cleanup

* fix: prettier formatting