Function render_form 

pub fn render_form(
    f: &mut Frame<'_>,
    area: Rect,
    state: &FormState,
    theme: &Theme,
)

Render the form inside area.

Each field takes up to 3 rows:

1. Label [*]: <input>
2. Description hint (only when focused, in Theme::hint)
3. Blank separator

The caller is responsible for wrapping this in a crate::popup::centered_popup

• crate::block::popup_block — no outer border is drawn here.