v1.103.1

Fixed

• Histograms rendered at hvplot's default 700×300 instead of the shared 600×600 used by every other plot type. HoloviewResult.set_default_opts() registered the default figure size for Curve, Points, Bars, Scatter, BoxWhisker, Violin, and HeatMap, but Histogram was missing so it escaped to hvplot's own default. Also registered Area and ErrorBars for consistency (ErrorBars would likewise escape when returned standalone from to_error_bar(); Area previously inherited the size only by virtue of being overlaid). The default-sized element list is now centralized in HoloviewResult.DEFAULT_SIZED_ELEMENTS and reused by both set_default_opts() and test_default_opts_cover_all_element_types, so the coverage guard stays in sync as new element types are added.