feat: add SSH command parser with comprehensive flag support

- Parse SSH commands from clipboard into domain.Server struct
- Support standard SSH flags (-p, -i, -l, -A, -X, -Y, -C, -4, -6, etc.)
- Support SSH -o options mapping to ssh_config fields
- Handle multiline commands with backslash continuation
- Extract lazyssh metadata (alias and tags) from comments
- Ignore regular comments (lines starting with #)
- Add comprehensive test coverage for various SSH command patterns

Author: tan9