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

api.http

@@ -0,0 +1,27 @@
+### Variables
+@host = http://localhost:8080
+@name = test-quarkus
+
+###
+# @name getStatus
+# Application status: version, uptime, JVM metrics
+GET {{host}}/status
+Accept: application/json
+
+###
+# @name getHealth
+# Aggregate MicroProfile Health (liveness + readiness)
+GET {{host}}/q/health
+Accept: application/json
+
+###
+# @name getReadiness
+# Liveness probe
+GET {{host}}/q/health/live
+Accept: application/json
+
+###
+# @name getLiveness
+# Readiness probe (includes application check)
+GET {{host}}/q/health/ready
+Accept: application/json