Placing an auto-numbered element or conductor advances a shared
NumerotationContext counter (QETProject::addConductorAutoNum/
addElementAutoNum) as a side effect that sat entirely outside the undo
stack. Undoing the placement removed the visible number but left the
counter advanced, so every undo of an auto-numbered placement silently
burned a number, with no way to get it back short of a manual reset.
Adds SetAutoNumContextCommand, a small QUndoCommand storing the old/new
NumerotationContext and calling the matching add*AutoNum() setter on
undo()/redo() -- the same shape QPropertyUndoCommand already uses next
to it in ConductorAutoNumerotation::applyText().
Wires it into the two conductor call sites (the static newProperties(),
and numerateNewConductor(), both in ConductorAutoNumerotation) and the
element call site (Element::setUpFormula(), called from
DiagramEventAddElement::addElement() when a new element is dropped onto
a diagram). setUpFormula() now takes an optional parent QUndoCommand;
addElement() calls it before pushing its own undo_object so the counter
change lands in the same undo macro as the element's placement -- one
Ctrl+Z reverts both together, instead of leaving the counter adrift.
The project-properties config dialog's own add*AutoNum() calls (editing
the numbering rule itself, not a side effect of placing something) are
deliberately left untouched, as are the load-time folio-sequential
bookkeeping calls in Diagram::loadElmtFolioSeq()/loadCndFolioSeq() and
the bulk folio-renumbering passes in QETProject -- none of those run as
part of an undoable user gesture.
Implements the scope proposed in discussion #608.
All export files that are derived from the project (BOM,
nomenclature, etc.) are saved in the same directory by default.
In this context, the standard directories have been grouped
together in qetapp.cpp / qetapp.h so that only one place needs
to be searched for in case of any adjustments.