build(core): add pitest profile targeting IoBounds

Extend the mutation-testing pilot to core, the home of the IoBounds bounds
primitive (ADR 0003 Phase E) that the reader file-structure guards delegate to.

IoBounds scores 15/15 mutations killed, test strength 100% — the existing
IoBoundsTest already pins every boundary of checkRange/toIntSize/checkCount,
and the primitive carries no redundant clause to begin with. Profile only;
no test changes needed.

Run: ./mvnw -pl core -P pitest verify

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: dfa1

core/pom.xml

@@ -176,6 +176,51 @@
 				</plugins>
 			</build>
 		</profile>
+
+		<!-- Mutation testing for the bounds primitive (ADR 0003 Phase E). Opt-in only:
+		     ./mvnw -pl core -P pitest verify
+		     Report: core/target/pit-reports/. -->
+		<profile>
+			<id>pitest</id>
+			<build>
+				<plugins>
+					<plugin>
+						<groupId>org.pitest</groupId>
+						<artifactId>pitest-maven</artifactId>
+						<version>1.20.0</version>
+						<dependencies>
+							<dependency>
+								<groupId>org.pitest</groupId>
+								<artifactId>pitest-junit5-plugin</artifactId>
+								<version>1.2.3</version>
+							</dependency>
+						</dependencies>
+						<executions>
+							<execution>
+								<id>pit-report</id>
+								<phase>verify</phase>
+								<goals>
+									<goal>mutationCoverage</goal>
+								</goals>
+							</execution>
+						</executions>
+						<configuration>
+							<targetClasses>
+								<param>io.github.dfa1.vortex.core.IoBounds</param>
+							</targetClasses>
+							<targetTests>
+								<param>io.github.dfa1.vortex.core.*</param>
+							</targetTests>
+							<outputFormats>
+								<param>HTML</param>
+								<param>XML</param>
+							</outputFormats>
+							<timestampedReports>false</timestampedReports>
+						</configuration>
+					</plugin>
+				</plugins>
+			</build>
+		</profile>
 	</profiles>
 
 </project>