Add manual conductor routing to the scripting API

Conductor::moveSegment(index, dx, dy) is the same primitive
handlerMouseMoveEvent()/handlerMouseReleaseEvent() apply on a drag --
move both axes on the target segment (each of ConductorSegment's
moveX()/moveY() silently no-ops on the wrong axis or a static,
terminal-anchored segment), recompute the path, and push one
ChangeConductorCommand undo step via the existing saveProfile().

Caught while writing the first test for it: moveSegment() never set
modified_path, so Conductor::toXml() skipped writing <segment> children
and a manually rerouted conductor silently reverted to auto-routing on
the very next save -- the change took effect in the running scene but
never reached disk. Fixed by setting the flag, the same as every other
path-modifying call site already does.

qet.conductorSegments() lists a conductor's segments (endpoints in
scene coordinates, orientation, static/movable) so a script can find
the index it wants; qet.moveConductorSegment() applies the move and
refuses a static segment or an out-of-range index.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

sources/scripting/qetscriptapi.h

@@ -402,6 +402,14 @@ class QetScriptApi : public QObject
 											  int terminalIndex, const QString &property,
 											  const QString &value);
 
+		// -- a conductor's own drawn path, not the whole potential's
+		// properties above -- one conductor only, addressed the same way --
+		Q_INVOKABLE QStringList conductorSegments(int folioIndex, const QString &elementUuid,
+												  int terminalIndex) const;
+		Q_INVOKABLE bool moveConductorSegment(int folioIndex, const QString &elementUuid,
+											  int terminalIndex, int segmentIndex,
+											  double dx, double dy);
+
 		// -- cross-references: master/slave and report links --
 		Q_INVOKABLE QString elementLinkType(int folioIndex, const QString &elementUuid) const;
 		Q_INVOKABLE QStringList linkedElements(int folioIndex, const QString &elementUuid) const;