build: add maven-release-plugin

Same config as rocksdbffm: autoVersionSubmodules, v@{project.version}
tag format, pushChanges=false (manual push after release:prepare).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: dfa1

pom.xml

@@ -272,6 +272,17 @@
 						</dependency>
 					</dependencies>
 				</plugin>
+				<plugin>
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-release-plugin</artifactId>
+					<version>3.3.1</version>
+					<configuration>
+						<autoVersionSubmodules>true</autoVersionSubmodules>
+						<tagNameFormat>v@{project.version}</tagNameFormat>
+						<pushChanges>false</pushChanges>
+						<localCheckout>true</localCheckout>
+					</configuration>
+				</plugin>
 			</plugins>
 		</pluginManagement>
 		<plugins>