Refactor specification handling in DocumentSettingsDialog and PDFController. Introduced primary application field for document types, updated export messages for consistency, and improved page number handling in specifications. Cleaned up unnecessary code in preview widgets.

view/documentsettingsdialog.h

@@ -133,6 +133,10 @@ private:
     QMap<QString, QComboBox*> m_decimalNumberComboBoxes;
     QMap<QString, QString> m_decimalNumberValues;
     
+    // Поля для "Первичное применение"
+    QComboBox *m_primaryApplicationComboBox;
+    int m_primaryApplicationFieldNumber;
+    
     // Статические данные о графах ГОСТ
     static QMap<int, QString> s_fieldNames;
     static QMap<int, QString> s_fieldDescriptions;
@@ -146,6 +150,12 @@ private:
     void onDecimalNumberComboBoxChanged(const QString &fieldName, const QString &value);
     void updateDecimalNumberFieldValue(const QString &type, const QString &value);
     
+    // Методы для работы с полем "Первичное применение"
+    void createPrimaryApplicationField();
+    void loadPrimaryApplicationSettings();
+    void savePrimaryApplicationSettings();
+    void onPrimaryApplicationComboBoxChanged(int fieldNumber, const QString &value);
+    
     // Методы для работы с настройками шрифта
     void createFontSettingsFields();
     void loadFontSettings();