Initialise the orientations of a default-constructed ConductorProfile

ConductorProfile's default constructor leaves beginOrientation and
endOrientation untouched, and the copy constructor and operator= then
read them from such a profile when a conductor's profiles are stored in
a QHash. UndefinedBehaviorSanitizer stops the binary there on every
project with conductors:

  conductorprofile.cpp:42:23: runtime error: load of value 1869263360,
  which is not a valid value for type 'Qet::Orientation'
    #0 ConductorProfile::ConductorProfile(ConductorProfile const&)
    #2 QHashPrivate::Node<Qt::Corner, ConductorProfile>::createInPlace

Give both members a default value, Qet::North, in the header. No
behaviour changes: a default-constructed profile is null (no segments)
and its orientations are never used before fromConductor() sets them.

No file-format change. Tests: the sanitizer build of the Linux CI job
(separate PR) fails on master with the report above and passes with
this change; all 23 example projects go through --export-svg and
--resave under ASan/UBSan on macOS without a report.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Signed-off-by: Beat Hangartner <beat@hangartners.ch>

sources/conductorprofile.h

@@ -38,10 +38,12 @@ class ConductorProfile {
 	public:
 	/// Segments composing the conductor
 	QList<ConductorSegmentProfile *> segments;
-	/// Orientation of the start terminal
-	Qet::Orientation beginOrientation;
+	/// Orientation of the start terminal. Initialised because the default
+	/// constructor leaves it as is, and the copy constructor and operator=
+	/// then read it from such a profile.
+	Qet::Orientation beginOrientation = Qet::North;
 	/// Orientation of the end terminal.
-	Qet::Orientation endOrientation;
+	Qet::Orientation endOrientation = Qet::North;
 	
 	// methods
 	public: