runtime(log): clean up and modernize log syntax

runtime(log): clean up and modernize log syntax

- Rename groups to consistent log* naming (LogString→logString, etc.)
- Remove redundant logOperator/logBrackets, use logSymbol for special chars
- Simplify level keywords by removing case variants
- Consolidate syslog column patterns into logSysColumn
- Move custom highlights to portable ctermfg/guifg names
- Update maintainer email address

closes: #19917

Signed-off-by: Mao-Yining <mao.yining@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>