clarify that the slip39 import passphrase applies to all shares and not individual ones

### src/main/java/com/sparrowwallet/sparrow/control/MnemonicKeystorePane.java
@@ -429,6 +429,14 @@ private boolean allPreviousWordsValid() {
         }
     }
 
+    protected String getPassphraseLabel() {
+        return "Passphrase:";
+    }
+
+    protected String getPassphraseHelpText() {
+        return "Advanced feature: a passphrase provides optional added security, but it is not stored so it must be remembered!";
+    }
+
     protected class PassphraseEntry extends HBox {
         private final TextField passphraseField;
 
@@ -457,7 +465,7 @@ public PassphraseEntry(boolean editable) {
                 }
             });
 
-            Label passphraseLabel = new Label("Passphrase:");
+            Label passphraseLabel = new Label(getPassphraseLabel());
             passphraseLabel.managedProperty().bind(passphraseLabel.visibleProperty());
             passphraseField = new TextField();
             passphraseField.setPromptText(passphraseProperty.isEmpty().get() ? "Leave blank for none" : "");
@@ -471,7 +479,7 @@ public PassphraseEntry(boolean editable) {
             HelpLabel helpLabel = new HelpLabel();
             helpLabel.setPrefHeight(28);
             helpLabel.setStyle("-fx-padding: 0 0 0 0");
-            helpLabel.setHelpText("Advanced feature: a passphrase provides optional added security, but it is not stored so it must be remembered!");
+            helpLabel.setHelpText(getPassphraseHelpText());
 
             getChildren().addAll(usePassphraseLabel, usePassphraseCheckbox, passphraseLabel, passphraseField, helpLabel);
         }

### src/main/java/com/sparrowwallet/sparrow/control/MnemonicShareKeystoreImportPane.java
@@ -305,6 +305,17 @@ private Node getDerivationEntry(List<ChildNumber> derivation) {
         return contentBox;
     }
 
+    @Override
+    protected String getPassphraseLabel() {
+        return "Global passphrase:";
+    }
+
+    @Override
+    protected String getPassphraseHelpText() {
+        return "Advanced feature: a passphrase provides optional added security, but it is not stored so it must be remembered!\n" +
+                "The passphrase applies to the reconstructed secret, and not to any individual share.";
+    }
+
     public static Glyph getIncompleteGlyph() {
         Glyph warningGlyph = new Glyph(FontAwesome5.FONT_NAME, FontAwesome5.Glyph.PLUS_CIRCLE);
         warningGlyph.getStyleClass().add("warn-icon");