docs: document LONGSWIPE variant in README and Javadoc

Author: ngonzalezpazFC

README.md

@@ -14,7 +14,8 @@ A toggle button component for Vaadin Flow that supports customizable labels and
 * Customizable left and right labels
 * Support for icons on both sides via slots
 * Optional label highlighting: active-side label uses the primary color, inactive side is dimmed
-* Theme variants: `SMALL`, `MEDIUM`, `LARGE`, `PRIMARY`, `SUCCESS`, `WARNING`, `ERROR`, `CONTRAST`
+* Theme variants: `SMALL`, `MEDIUM`, `LARGE`, `LONGSWIPE`, `PRIMARY`, `SUCCESS`, `WARNING`, `ERROR`, `CONTRAST`
+* `LONGSWIPE` variant produces a wider switch track, optimized for touch interaction; can be combined with size variants
 * Fluent API for easy configuration
 * Full integration with Vaadin's `HasValue`, `HasSize`, `HasLabel`, `HasAriaLabel`, and `HasTooltip`
 
@@ -131,6 +132,10 @@ FCToggleButton toggle = new FCToggleButton()
 // Apply theme variants
 toggle.addThemeVariants(FCToggleButtonVariant.PRIMARY);
 toggle.addThemeVariants(FCToggleButtonVariant.CONTRAST);
+
+// Long swipe: wider track, optimized for touch (can be combined with size variants)
+toggle.addThemeVariants(FCToggleButtonVariant.LONGSWIPE);
+toggle.addThemeVariants(FCToggleButtonVariant.LONGSWIPE, FCToggleButtonVariant.LARGE);
 ```
 
 ## Special configuration when using Spring

src/main/java/com/flowingcode/vaadin/addons/fctogglebutton/FCToggleButtonVariant.java

@@ -24,17 +24,33 @@
 /**
  * Theme variants for the {@link FCToggleButton} component.
  *
+ * <p>Size variants ({@link #SMALL}, {@link #MEDIUM}, {@link #LARGE}) and {@link #LONGSWIPE} can be
+ * combined (e.g. {@code LONGSWIPE} + {@code LARGE}).
+ *
  * @since 1.0.0
  */
 public enum FCToggleButtonVariant implements ThemeVariant {
+    /** Renders the toggle at a smaller size (32×18 px track). */
     SMALL("small"),
+    /** Renders the toggle at the default medium size (44×24 px track). */
     MEDIUM("medium"),
+    /** Renders the toggle at a larger size (56×32 px track). */
     LARGE("large"),
+    /**
+     * Renders a wider switch track optimized for touch interaction. Can be combined with size
+     * variants: the track width is increased by 28 px while preserving the height of the chosen
+     * size.
+     */
     LONGSWIPE("longswipe"),
+    /** Applies the primary color to the checked state. */
     PRIMARY("primary"),
+    /** Applies the success color to the checked state. */
     SUCCESS("success"),
+    /** Applies the warning color to the checked state. */
     WARNING("warning"),
+    /** Applies the error color to the checked state. */
     ERROR("error"),
+    /** Applies the contrast color to the checked state. */
     CONTRAST("contrast");
 
     private final String variant;