My supervisor spells my name incorrectly I've discovered that every time my supervisor has cited any of the papers or technical documents I've written she/he would:


spell my name incorrectly or forget to add my name
spell the article/technical document title incorrectly


These are citation made in articles already published (!!) or at final stage (where she/he denied to make any effort to try to correct them). Althought this means she/he also loses citations of these articles she/he is doing mistakes only on my papers/technical documents, not with others. 

I am obliged to add her/him in every paper as co-author, although she/he never engages in any discussion concerning any of the papers or phd. This is not someone that has a flock of PhD and MSc students under her/his wings, the number of students are really reduced.

How should I react to this? What should I do about it?
Mis-citing articles (and worse, removing authors) is one of those crimes that academics take very seriously (and no one else really understands). If you were a collaborator, then repeated behavior of this kind would get your advisor in trouble not just with you, but with editors at the journals, reviewers, and so on. 

So you really should bring it up. 

How do you go about doing it ? Because it's your advisor, you have to be a little more gentle: some options:


keeping it specific to each mis-cite: "I noticed you cited my work, but you omitted my name: can you please fix it". It sounds like you've been doing this already though. 
the technical solution: "Here's a BibTeX file containing all my papers: you can use that for citing" - this works only if your advisor uses some kind of citation manager to cite papers. 
the direct solution: "I noticed that in this, this and this paper, you omitted my name from the citation. I'd really appreciate it if you could contact the editors and submit a correction: I'd like to get credit for my work". 


In other words, keep the discussion focused on outcomes and actions, rather than intent (because a) it's hard to argue intent, and b) you're in a position of weakness)