feat: add support for HTML <abbr> element (#14882) (#22574)

Add native Vaadin Flow support for the HTML abbreviation element to improve accessibility and eliminate the need for custom workarounds.

- Add ABBR constant to Tag interface
- Create Abbr component extending HtmlContainer with ClickNotifier
- Add comprehensive test suite via AbbrTest
- Support for title attribute inherited from HtmlComponent

The component provides three constructors for flexible usage:
empty, text-based, and component-based initialization.

Fixes #14882

Author: Artur-

flow-html-components/src/main/java/com/vaadin/flow/component/html/Abbr.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2000-2025 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.flow.component.html;
+
+import com.vaadin.flow.component.ClickNotifier;
+import com.vaadin.flow.component.Component;
+import com.vaadin.flow.component.HtmlContainer;
+import com.vaadin.flow.component.Tag;
+
+/**
+ * Component representing a <code>&lt;abbr&gt;</code> element.
+ *
+ * @author Vaadin Ltd
+ */
+@Tag(Tag.ABBR)
+public class Abbr extends HtmlContainer implements ClickNotifier<Abbr> {
+
+    /**
+     * Creates a new empty abbreviation.
+     */
+    public Abbr() {
+        super();
+    }
+
+    /**
+     * Creates a new abbreviation with the given child components.
+     *
+     * @param components
+     *            the child components
+     */
+    public Abbr(Component... components) {
+        super(components);
+    }
+
+    /**
+     * Creates a new abbreviation with the given text.
+     *
+     * @param text
+     *            the text
+     */
+    public Abbr(String text) {
+        super();
+        setText(text);
+    }
+}

flow-html-components/src/test/java/com/vaadin/flow/component/html/AbbrTest.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2000-2025 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.flow.component.html;
+
+import org.junit.Test;
+
+public class AbbrTest extends ComponentTest {
+    // Actual test methods in super class
+
+    @Override
+    protected void addProperties() {
+        // Component defines no new properties
+    }
+
+    @Test
+    @Override
+    public void testHasAriaLabelIsNotImplemented() {
+        // Don't use aria-label or aria-labelledby on any other non-interactive
+        // content such as p, legend, li, or ul, because it is ignored.
+        // Source: https://www.w3.org/TR/using-aria/#label-support
+        super.testHasAriaLabelIsNotImplemented();
+    }
+}

flow-server/src/main/java/com/vaadin/flow/component/Tag.java

@@ -38,6 +38,10 @@
      * Tag for an <code>&lt;a&gt;</code>.
      */
     String A = "a";
+    /**
+     * Tag for an <code>&lt;abbr&gt;</code>.
+     */
+    String ABBR = "abbr";
     /**
      * Tag for an <code>&lt;article&gt;</code>.
      */