Fix the M and F mirror keys doing nothing on a folio

#1346 rebuilt the Edit menu from a list of named actions, written before
#1354 added Horizontal mirror and Vertical mirror. The two actions ended up
in no menu and on no toolbar, so their shortcuts (M, F) never fired; only
the right-click menu reached them. Add both to the Edit menu after
"Choose texts orientation".

Also correct two labels left behind by later changes:
- Settings > General: the fine-movement step is now used with Ctrl, not
  Alt (#1395).
- Terminal editor tooltip: the checkbox is now called "Function
  separation" (#1456).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

sources/editor/ui/terminaleditor.ui

@@ -88,7 +88,7 @@
    <item row="4" column="1">
     <widget class="QLineEdit" name="m_potential_le">
      <property name="toolTip">
-      <string>No effect unless "Potential isolation" is checked (all terminals of the block then stay connected). When it is checked, terminals sharing the same value stay connected to each other and the others are isolated.</string>
+      <string>No effect unless "Function separation" is checked (all terminals of the block then stay connected). When it is checked, terminals sharing the same value stay connected to each other and the others are isolated.</string>
      </property>
     </widget>
    </item>

sources/qetdiagrameditor.cpp

@@ -1577,6 +1577,8 @@ void QETDiagramEditor::setUpMenu()
 	menu_edition -> addAction(m_rotate_selection);
 	menu_edition -> addAction(m_rotate_group_selection);
 	menu_edition -> addAction(m_rotate_texts);
+	menu_edition -> addAction(m_mirror_horizontal);
+	menu_edition -> addAction(m_mirror_vertical);
 	menu_edition -> addAction(m_find_element);
 	menu_edition -> addAction(m_edit_selection);
 	QMenu *group_menu = menu_edition -> addMenu(QET::Icons::textGroup, tr("Group", "fr: Grouper"));

sources/ui/configpage/generalconfigurationpage.ui

@@ -1225,7 +1225,7 @@
        <item>
         <widget class="QGroupBox" name="groupBox_4">
          <property name="title">
-          <string>Keyboard movement with the ALT key: 1 - 9</string>
+          <string>Keyboard movement with the Ctrl key: 1 - 9</string>
          </property>
          <layout class="QGridLayout" name="gridLayout_11">
           <item row="0" column="1">