"bar" (horizontal) and "column" (vertical) both map to
TraceType.BAR. MAIDR does not currently distinguish
bar orientation at the trace-type level.area, step-area, spline-area) map to
TraceType.LINE. The fill is lost in the conversion; a
runtime warning is emitted so developers are aware.
Map AnyChart series type strings to MAIDR TraceType values.
AnyChart uses lowercase type names such as "bar", "line", "column", etc. Multi-word types are normalised to kebab-case before lookup. This mapping covers the chart types that MAIDR currently supports.