build: replace scaffold Dockerfiles with native multi-stage image

- Add Dockerfile using Mandrel jdk-21 builder and quarkus-micro-image:2.0 runtime
- Run as non-root user 1001, expose 8080, set TZ=America/Santiago
- Bind http host to 0.0.0.0 for container networking
- Remove obsolete Quarkus-generated Dockerfiles (jvm, legacy-jar, native, native-micro)
- Tighten .dockerignore to ship only build inputs (mvnw, .mvn, pom.xml, src)
- Add api.http with /status and /q/health request samples

.dockerignore

@@ -1,5 +1,9 @@
-*
-!target/*-runner
-!target/*-runner.jar
-!target/lib/*
-!target/quarkus-app/*
+**
+!mvnw
+!mvnw.cmd
+!.mvn
+!pom.xml
+!src
+!Dockerfile
+!api.http
+!README.md