<feature>[build]: register zr-agent in build aggregator

Add the premium zr-agent module as a managed dependency in
build/pom.xml so the all-in-one distribution bundles the new MN
Agent Gateway v1 plugin.

The zr-agent module (plugin-premium/zr-agent) implements the MN
side of the dual-track ZRM <-> kvmagent gateway contract (sync via
/internal/zrm/v1/agent-call-sync, async via
/internal/zrm/v1/agent-call + poll). Without this registration the
plugin jar is built but not pulled into the assembly, and ZRM
calls land on a MN that has no /internal/zrm/v1/* handler.

Resolves: ZSV-12345

Change-Id: I68766f6d7363796f656a6f70706371647565736a

Author: taogan21

build/pom.xml

@@ -528,6 +528,11 @@
                     <artifactId>zmigrate-plugin</artifactId>
                     <version>${project.version}</version>
                 </dependency>
+                <dependency>
+                    <groupId>org.zstack</groupId>
+                    <artifactId>zr-agent-plugin</artifactId>
+                    <version>${project.version}</version>
+                </dependency>
                 <dependency>
                     <groupId>org.zstack</groupId>
                     <artifactId>zsv</artifactId>