516 compatibility for browsers (#20652)

this is a bit of

https://github.com/cmss13-devs/cmss13/pull/8646
https://github.com/cmss13-devs/cmss13/pull/8875
https://github.com/cmss13-devs/cmss13/pull/8606
https://github.com/cmss13-devs/cmss13/pull/8607
https://github.com/cmss13-devs/cmss13/pull/8359
https://github.com/cmss13-devs/cmss13/pull/7860
( and thus https://github.com/ParadiseSS13/Paradise/pull/25105
https://github.com/ParadiseSS13/Paradise/pull/25205
https://github.com/ParadiseSS13/Paradise/pull/25363
https://github.com/ParadiseSS13/Paradise/pull/26423 and
https://github.com/ParadiseSS13/Paradise/pull/26433 )
https://github.com/tgstation/tgstation/pull/89766

in order to work properly - using the efficient storage method, instead
of the byond json method - github pages needs to be enabled and built
from the gh-pages branch. because yeah

---------

Co-authored-by: harryob <55142896+harryob@users.noreply.github.com>

code/modules/security levels/keycard authentication.dm

@@ -87,7 +87,7 @@
 		dat += "<p><A href='byond://?src=[REF(src)];reset=1'>Back</A>"
 
 
-	user << browse(dat, "window=keycard_auth;size=500x350")
+	user << browse(HTML_SKELETON(dat), "window=keycard_auth;size=500x350")
 	return