Fix Automatic-Module-Name without hypens

Signed-off-by: Daniel Garnier-Moiroux <git@garnier.wf>

mcp/pom.xml

@@ -20,6 +20,30 @@
 		<developerConnection>scm:git:ssh://git@github.com/modelcontextprotocol/java-sdk.git</developerConnection>
 	</scm>
 
+	<properties>
+		<module.name>io.modelcontextprotocol.sdk.mcp</module.name>
+	</properties>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<executions>
+					<!-- module-info.java refers to the sibling modules by their JPMS names, and
+					     those only exist once the siblings have been packaged as jars: before
+					     the package phase the reactor hands the compiler bare target/classes
+					     directories, which cannot be automatic modules. Compiling at
+					     prepare-package keeps `mvn test` working on the full reactor. -->
+					<execution>
+						<id>java-compile</id>
+						<phase>prepare-package</phase>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+
 	<dependencies>
 
 		<dependency>