Danish translation notes

No blocking translation issues found.

A few terms involved product-style judgment calls:

notes.title / nav.notes → "Tavle" to match the family-planner/board feel better than a literal "Noter".
housekeeping.title → "Rengøringsområde" while navigation keeps "Rengøring" for shorter UI labels.
dashboard.title / nav.dashboard → "Oversigt" to stay natural in Danish UI copy.
Existing non-English source strings inside en.json (mainly a few German settings labels) were translated into Danish from their apparent UI meaning.

Verified:

public/locales/da.json parses as valid JSON.
da.json matches en.json key structure exactly.
Placeholder tokens such as {{name}}, {{count}}, {{date}}, and {{title}} were preserved exactly.