Box object - Represents a rectangular area on the chart
xloc: "bar_index" | "bar_time"
X-axis coordinate system
extend: "none"
| "left"
| "right"
| "both"
Horizontal extension mode
border_color: color
Border color (stored but not used for calculations)
border_width: number
Border width in pixels (stored but not used for calculations)
border_style: "solid"
| "dotted"
| "dashed"
Border style (stored but not used for calculations)
text_color: color
Text color
text_halign: "left"
| "center"
| "right"
Horizontal text alignment
text_valign: "top"
| "center"
| "bottom"
Vertical text alignment
text_wrap: "none" | "auto"
Text wrapping mode
text_font_family: "default" | "monospace"
Text font family