Add internationalization (DE + EN) to previously missing apps:
- todo: task management translations
- skilltree: skill/XP system translations
- nutriphi: nutrition tracking translations
- planta: plant care translations
- questions: research app translations
- matrix: chat client translations (layout integration)
Each app includes:
- svelte-i18n setup with SSR support
- localStorage persistence ({app}_locale pattern)
- i18n loading state in +layout.svelte
- German (default) and English translations
Updated CONSISTENCY_REPORT.md to mark i18n task as complete.
Also includes:
- mana-tts service placeholder files
