Function draw_block_frame 

pub fn draw_block_frame(
    bbox: Rect,
    title: &ShapeLabel<'_>,
    paint: BlockPaint,
    painter: &mut Style<'_, impl Renderer>,
)

Draw a block’s body: the outline fill, then the title. Drawn before the block’s pins and labels so its opaque fill sits under them, never over them. The type label is left to the caller (it is block-only; ports/areas that share this frame have no type).