refactor: deprecate Board (#7866)

* refactor: deprecate Board

* Apply suggestions from code review

---------

Co-authored-by: Serhii Kulykov <[email protected]>

Author: sissbruecker

vaadin-board-flow-parent/vaadin-board-flow/src/main/java/com/vaadin/flow/component/board/Board.java

@@ -24,11 +24,14 @@
  * Row consists of four columns, and can contain up to four components taking
  * one column each, or fewer components with multiple columns each as long as
  * sum of columns stays less than or equal to four.
- * <p>
+ *
+ * @deprecated Board is deprecated and will be removed in Vaadin 26. Consider
+ *             using Dashboard as an alternative.
  */
 @Tag("vaadin-board")
 @NpmPackage(value = "@vaadin/board", version = "25.0.0-alpha15")
 @JsModule("@vaadin/board/src/vaadin-board.js")
+@Deprecated(since = "25.0", forRemoval = true)
 public class Board extends Component
         implements HasSize, HasStyle, HasOrderedComponents {
 

vaadin-board-flow-parent/vaadin-board-flow/src/main/java/com/vaadin/flow/component/board/Row.java

@@ -26,11 +26,13 @@
  * taking one column each, or fewer components with multiple columns each as
  * long as sum of columns stays less than or equal to four.
  *
- * <p>
+ * @deprecated Board Row is deprecated and will be removed in Vaadin 26.
+ *             Consider using Dashboard as an alternative.
  */
 @Tag("vaadin-board-row")
 @NpmPackage(value = "@vaadin/board", version = "25.0.0-alpha15")
 @JsModule("@vaadin/board/src/vaadin-board-row.js")
+@Deprecated(since = "25.0", forRemoval = true)
 public class Row extends Component
         implements HasStyle, HasSize, HasOrderedComponents {