Naomi

• Added a new light theme and dark theme optimized for OLED displays

Junko

• Fixed critical crash in older Android devices
• Fixed critical crash using German and Belarusian languages

Honoka

• Cyrillic input for Russian and Ukrainian languages
• Fixed adaptive screen scaling

Closes #38
Closes #18

Ayumi

• Fixed zu and ji in reverse mode #33
• Added sound null safety
• Updated packages and SDK
• Integrated Turkish language

Koko

• Added reverse quiz (Rōmaji to Kana)
• Fixed quiz after back to main menu
• Minor UI changes

Hikari

• The selected Kana sets are remembered
• Added UI translation

Shika

• Spaced repetition algorithm
• The keyboard does not close after submit
• New icon

Reiko

• Set selection in Hiragana and Katakana
• Improved quiz core
• Fixed "ri" Katakana
• Improved dark style

Natsuko

Fixed some errors.