Add German/English word list structure

[Hartwich]

Goal

Add or improve German/English word list support for Tabu.

Codex Auftrag

Use small original/example lists only if needed and prepare a clear import structure.

Focus

• separate word/content files by language
• support at least German and English
• avoid unclear third-party word lists
• include only small original/example lists if needed
• document where larger reviewed word lists can be added later

Acceptance Criteria

• Language-specific word lists are clearly separated.
• Existing gameplay still works.
• No unclear third-party copyrighted word lists are added.
• npm run typecheck passes.
• npm run build passes.

Safety

Do not add copyrighted, unclear, or unreviewed third-party assets or content.