git-master skill: language detection assumes only English/Korean

[s2mr]

Problem

The git-master skill's language handling is currently written as if only English and Korean exist:

• Phase 1.1 Language Detection counts Korean vs English commits and decides KOREAN or ENGLISH
• Phase 5.4 Commit Message Generation branches on language == KOREAN or language == ENGLISH with no fallback
• Mode detection examples only show Korean as the non-English example
• History search and rebase trigger tables only include Korean translations

This makes the skill misleading or confusing for Japanese, Chinese, Spanish, etc. repositories.

Expected Behavior

Language detection should be language-agnostic — it should detect the dominant language/script used in the repository's commit history and produce commit messages matching that style, regardless of which language it is.

Proposed Fix

• Replace the binary Korean/English detection with a generic "dominant language profile" approach
• Show multilingual examples (English, Japanese, Korean, etc.) as illustrative rather than as hardcoded output targets
• Update all trigger tables to include Japanese/other language examples

A PR fixing this is at #3096.