Merge remote-tracking branch 'upstream/master' into wiring-manager

Conflicts resolved in 24 files. Notable decisions:

- ico/icon-themes.qrc: upstream's icon folder restructure kept; the 36
  cable icon entries re-added under the new qet/qet-dark path scheme
  (XML valid, every referenced file exists).
- Toolbar system: upstream's DiagramToolbarSettings now owns the
  toolbar filling. The cable tool is registered as
  diagrameditor.add_cable (generic group loop) and listed on the
  "diagram" toolbar right after the auto-break conductor action,
  separated by a divider, exactly like before the merge.
- Paste: the cable lines of a copy are handed to
  PasteNumberingImport::push() as extra commands, so paste + cable
  lines + the numbering question stay ONE undo step on both paste
  paths (DiagramView::paste and DiagramEventAddPaste::commit).
- PDF links: upstream's deterministic link sorting kept together with
  the cable cross-reference injector (injectLinkTo -> links list).
- Element renumbering: upstream's ElementAutoNumSchemeCommand::renumber
  replaces the old formula-based body of
  QETProject::renumberElementsBySchemeTitle; the cable numbering rule
  API (cableAutoNum, axis priority, rule name) is kept in full.
- Auto-numbering pages: upstream's scheme management kept, the Câbles
  tab added as index 4 (changeToCableTab), both entry points
  changeToCable() and changeToElement() kept side by side.
- SelectAutonumW: dirty tracking and the contextEdited signal moved
  into upstream's insertPartRow() row API, so single-rule mode, the
  rule-removable button and "confirm without change leaves the project
  alone" keep working.
- xrefpropertieswidget: upstream's offset clamping kept; the cable
  branch (Texte field, Police button, hidden display options) kept;
  the stack-overlapping checkbox is hidden for cables.

Verified after the merge: build green (515/515, no errors), ctest
85/86 (only the pre-existing headless tst_menubarkeyboard failure),
offscreen smoke exit 124.

sources/ui/projectpropertiesdialog.cpp

@@ -107,3 +107,15 @@ void ProjectPropertiesDialog::changeToCable()
 				m_properties_dialog->pages.at(2));
 	autoNumPage->changeToCableTab();
 }
+
+/**
+	@brief ProjectPropertiesDialog::changeToElement
+	Change the current displayed tab to the element numberings tab.
+*/
+void ProjectPropertiesDialog::changeToElement()
+{
+	ProjectAutoNumConfigPage *autoNumPage =
+			static_cast <ProjectAutoNumConfigPage*>(
+				m_properties_dialog->pages.at(2));
+	autoNumPage->changeToTab(2);
+}