Function t 

pub fn t(app: &AppState, key: &str) -> String

What: Get a translation for a given key from AppState.

Inputs:

• app: AppState containing translation maps
• key: Dot-notation key (e.g., “app.titles.search”)

Output:

• Translated string, or the key itself if translation not found

Details:

• Uses translations from AppState
• Falls back to English if translation missing