Facet map with just one panel does not include panel title

[Nowosad]

@mtennekes -- see the example below. My assumption is that the panel title would always be shown when the tm_facets() is applied (consistency).

library(tmap)

tm_shape(World) +
  tm_polygons() +
  tm_facets("continent")

# facet map with one panel does not include panel title
europe = subset(World, continent == "Europe")
tm_shape(europe) +
  tm_polygons()  +
  tm_facets("continent")

^{Created on 2025-12-01 with reprex v2.1.1}