[bug] v0.5-dev+refactor bugs (investigation in progress)

[kvid]

I'm afraid this task investigating what works and what don't in the dev branch is more time consuming than expected. If anyone want to help collecting/creating some extra test cases (YAML input) for fuctionality not covered by existing examples, and checking the outputs from the existing and new test cases using both the latest release and the dev branch, please comment here. There are of course a lot of intended differences due to the different way of building HTML output, but the resulting look should be mainly similar. Create a new task if needed, and we can link it as a sub-task. Using AI to help is of course legal, but please make a note on what part of the work is done by AI.

1. Commit f5c00fa should have reapplied Rename placehoder "sheetsize_default" to <!-- %template_sheetsize% --> #380 changes (f5c00fa) onto the dev branch, but a lot of extra changes to din-6771.html is also done, including inserting a space between < and !-- in the fontname and bgcolor placeholders, that makes them both fail to work as intended. I suspect some kind of automatic reformatter has been used, and that it didn't accept the WireViz placeholder syntax.
2. It seems the Qty values of cable BOM entries are computed wrongly. The values seems to be a count of cable instances, not the sum of their lengths.
3. TODO: Add extra issues here when detected.