Move the pure-header utilities shared by app/ and engine/ out of
engine/common/ into a new shared/include/oakutil/ layer (define, lerp,
decibel, digit, range, crashpadutils, autoscroll, qtutils, filefunctions
declarations, and a trimmed xmlutils exposing a CancelAtom-free void*
overload). engine/common/ keeps forwarding headers so internal include
paths are unchanged; app/ now includes oakutil/* directly.
engine/node/project.h gains an explicit NodeGroup forward declaration
previously obtained transitively through the old xmlutils.h.
- slider DisplayType enums sink to node/sliderdisplaytype.h (canonical
engine home); FloatSlider/RationalSlider alias them for compatibility
- DropWithoutSequenceBehavior enum sinks to common/dropworkflowbehavior.h
- Config errors now go through a registered ErrorHandler hook instead of
QMessageBox with a MainWindow parent; the style default no longer
depends on the UI style manager
- MainWindowLayoutInfo moves to node/project/serializer/ and its panel
dependency is reduced to a plain std::map alias (PanelLayoutInfo),
breaking the engine -> PanelWidget -> KDDockWidgets chain
- ProjectImportErrorDialog moves from task/ to dialog/projectimport/
- remove confirmed-redundant UI includes and give project.h/import.h/
project.cpp the direct includes they were borrowing transitively
- project.h includes folder/sequence headers directly (it used both
types in its own API all along)
Mike-Solar