tl;dr: Is there a way to forcibly override the page number settings of any existing style sheet?
I frequently find myself in the following situation: I am writing a report or paper of some kind using an external style sheet that cannot be modified (think, thesis, journal submission, etc.). There are page limits, but the external style removes all page numbers. So, when writing, I have no idea how many pages I have used or what page I am on.
So, I've been trying to find a way to add page numbers back to the document, overriding any previous settings set by the external style sheet. Before submitting, I will remove this so the original style is preserved. Of course, the solution should not depend on the style. I am looking for a global solution that would apply to any (or, say almost any if there are pathological edge cases) document and style.