CLAUDE: opt-in -Plibtorch Maven profile to unpack libtorch from the mirror (piece 4B)

Adds an OFF-by-default profile that dependency:unpacks the libtorch native runtime
(org.pytorch:libtorch-cxx11-cu128:2.7.1:zip, cu128) from mirror.elphel.com/maven-dependencies
into target/libtorch-dist for the native DNN backend (libtpdnn.so / CuasDnnLocal) on a
deployment box. The default build never downloads the 3.8GB zip.

Artifact published to the mirror in maven layout (server-side copy of the existing zip)
via tile_processor_gpu/jna/publish_libtorch_mirror.sh. Verified: zip + .pom reachable at
the computed maven URL (HTTP 200, 3.78GB), profile parses (mvn -Plibtorch validate OK).
Full unpack deferred (redundant on this box - libtorch already extracted); exercises on
first deployment machine via `mvn -Plibtorch generate-resources`.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

pom.xml

@@ -320,7 +320,41 @@
 		            -->
 	           	</dependencies>
 	        </profile>
-		</profiles>	
+	        <!-- Opt-in (mvn -Plibtorch ...): unpack the libtorch native runtime (cu128, ~3.8GB zip) from the
+	             Elphel mirror into target/libtorch-dist for the native DNN backend (libtpdnn.so / CuasDnnLocal).
+	             OFF by default so the normal build never downloads it. Publish the artifact to the mirror with
+	             tile_processor_gpu/jna/publish_libtorch_mirror.sh. By Claude on 06/27/2026. -->
+	        <profile>
+	            <id>libtorch</id>
+	            <build>
+	                <plugins>
+	                    <plugin>
+	                        <groupId>org.apache.maven.plugins</groupId>
+	                        <artifactId>maven-dependency-plugin</artifactId>
+	                        <version>3.1.2</version>
+	                        <executions>
+	                            <execution>
+	                                <id>unpack-libtorch</id>
+	                                <phase>generate-resources</phase>
+	                                <goals><goal>unpack</goal></goals>
+	                                <configuration>
+	                                    <artifactItems>
+	                                        <artifactItem>
+	                                            <groupId>org.pytorch</groupId>
+	                                            <artifactId>libtorch-cxx11-cu128</artifactId>
+	                                            <version>2.7.1</version>
+	                                            <type>zip</type>
+	                                            <outputDirectory>${project.build.directory}/libtorch-dist</outputDirectory>
+	                                        </artifactItem>
+	                                    </artifactItems>
+	                                </configuration>
+	                            </execution>
+	                        </executions>
+	                    </plugin>
+	                </plugins>
+	            </build>
+	        </profile>
+		</profiles>
 
 	<build>
 		<resources>