Function ratatui_chart_begin

#[no_mangle]
pub extern "C" fn ratatui_chart_begin(
    handle: *mut c_void,
    area_id: u32,
)

Starts a Chart builder.

Builder lifecycle:

1. ratatui_chart_begin — open the builder for area_id.
2. Optionally ratatui_chart_x_axis and/or ratatui_chart_y_axis — set axis titles and bounds.
3. Zero or more ratatui_chart_dataset calls — add datasets.
4. ratatui_chart_end — flush the builder into the command queue.

Only one chart builder may be active at a time per handle.