fix: downgrade to Java 17 for CI build compatibility

Build container has JDK 17, not 21. Also replaced
Thread.ofVirtual() (Java 21) with standard Thread.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Dockerfile

@@ -1,4 +1,4 @@
-FROM --platform=$BUILDPLATFORM maven:3.9-eclipse-temurin-21 AS backend-build
+FROM --platform=$BUILDPLATFORM maven:3.9-eclipse-temurin-17 AS backend-build
 WORKDIR /build
 COPY pom.xml .
 RUN mvn dependency:go-offline -B || true
@@ -14,7 +14,7 @@ RUN echo "//gitea.siegeln.net/api/packages/cameleer/npm/:_authToken=${REGISTRY_T
 COPY ui/ .
 RUN npm run build
 
-FROM eclipse-temurin:21-jre
+FROM eclipse-temurin:17-jre
 WORKDIR /app
 COPY --from=backend-build /build/target/cameleer-deploy-demo-*.jar /app/server.jar
 COPY --from=ui-build /ui/dist /app/static

pom.xml

@@ -18,7 +18,7 @@
     <description>Demo: upload Camel JARs, build containers with agent injection, deploy to K8s</description>
 
     <properties>
-        <java.version>21</java.version>
+        <java.version>17</java.version>
     </properties>
 
     <dependencies>

src/main/java/com/cameleer/deploy/service/DeployService.java

@@ -103,7 +103,7 @@ public class DeployService {
         buildLogs.put(name, Collections.synchronizedList(new ArrayList<>()));
 
         // Run pipeline async
-        Thread.ofVirtual().name("deploy-" + name).start(() -> {
+        var thread = new Thread(() -> {
             try {
                 runPipeline(name, jarFile.getBytes(), imageName, imageTag, resources, envVars);
             } catch (Exception e) {
@@ -111,7 +111,9 @@ public class DeployService {
                 appendLog(name, "FATAL: " + e.getMessage());
                 apps.computeIfPresent(name, (k, v) -> v.withStatus(DeployStatus.FAILED, e.getMessage()));
             }
-        });
+        }, "deploy-" + name);
+        thread.setDaemon(true);
+        thread.start();
 
         return app;
     }