Please add a Lua function similar to mw.wikibase.getEntityObject for getting an entity by site link (title), just like Special:ItemByTitle or the wbgetentities API module with titles parameter.
On cswiki articles translated from other language wikis are marked by Translated template (with source wiki, article and revision parameters filled in). The template could detect (using Module:Wikidata), whether the article is connected with that source article and categorize it if not. But if that source article is connected with a different article, it is false positive there (could be categorized too, but in a different maintenance category). I can not single out these false positives, because I can not find out (using Lua function in Module:Wikidata) the Q-id for a given wiki:page.
On enwiki in Module:Wikidata talk page is another request from @czar: QID lookup from enwp article title.