convertor/tests
Ryo 0abd934046 fix: make CJK font conditional and locale-aware
Address code review feedback from cubic-dev-ai:

P1: Unconditionally passing CJKmainfont broke non-CJK conversions in
environments without CJK fonts. Now the source file is scanned for CJK
characters and the font argument is only added when CJK content is
detected.

P2: Hardcoded Noto Sans CJK SC only covers Simplified Chinese. Now
detects the specific CJK language (Japanese Kana, Korean Hangul, or
Chinese Hanzi) and selects the appropriate font variant (JP/KR/SC).

Changes:
- Add detectCJKFont() that reads the source file and returns the
  correct Noto Sans CJK variant, or null for non-CJK content
- CJK font argument is only added when detectCJKFont returns non-null
- Detection order: Japanese (Kana) > Korean (Hangul) > Chinese (Hanzi)
  since Japanese also uses Kanji shared with Chinese
- Graceful fallback: if file can't be read, no CJK font is added
- Update tests to use temp files with real CJK content (11 tests total)
2026-07-02 10:23:16 +08:00
..
converters fix: make CJK font conditional and locale-aware 2026-07-02 10:23:16 +08:00