fix: Ensure SSH aliases are properly parsed and displayed

[songpinru]

This commit fixes an issue where SSH aliases defined in the config file weren't being correctly parsed and displayed. The problem was that the host processing flow was causing multi-pattern hosts to be split, resulting in aliases being lost.

Changes:

• Extract core host processing logic into a dedicated process_hosts() function
• Modify the host processing flow to preserve original multi-patterns as aliases
• Add unit tests to verify correct alias handling
• Update comments to English for consistency

Fixes SSH alias display in the UI where aliases were showing as separate lines with empty alias columns.