Function translate 

pub fn translate(key: &str, translations: &TranslationMap) -> Option<String>

What: Look up a translation in the translation map.

Inputs:

• key: Dot-notation key (e.g., “app.titles.search”)
• translations: Translation map to search

Output:

• Option<String> containing translation or None if not found

Details:

• Direct key lookup
• Returns None if key not found