fix(collection): isCustomCollection() false-positive on company path

The default user-collection path ends in "elements" and the default
company-collection path ends in "elements-company".  Both
FileElementCollectionItem::isCustomCollection() and
ElementsLocation::isCustomCollection() used startsWith(customDir),
so "…/elements-company/…" matched "…/elements" and returned true.

This caused ElementsCollectionModel::addLocation() to insert a
newly-saved user-collection element as a child of the company-
collection branch in the tree, making it appear in the wrong panel.

Fix: require the path to equal the directory root exactly, or to
start with the directory root followed by '/'.

  path == dir || path.startsWith(dir + QLatin1Char('/'))

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

sources/ElementsCollection/elementslocation.cpp

@@ -523,7 +523,9 @@ bool ElementsLocation::isCompanyCollection() const
 */
 bool ElementsLocation::isCustomCollection() const
 {
-	return fileSystemPath().startsWith(QETApp::customElementsDirN());
+	const QString dir = QETApp::customElementsDirN();
+	const QString path = fileSystemPath();
+	return path == dir || path.startsWith(dir + QLatin1Char('/'));
 }
 
 /**

sources/ElementsCollection/fileelementcollectionitem.cpp

@@ -274,7 +274,9 @@ bool FileElementCollectionItem::isCompanyCollection() const
 */
 bool FileElementCollectionItem::isCustomCollection() const
 {
-	return fileSystemPath().startsWith(QETApp::customElementsDirN());
+	const QString dir = QETApp::customElementsDirN();
+	const QString path = fileSystemPath();
+	return path == dir || path.startsWith(dir + QLatin1Char('/'));
 }
 
 /**