refactor: use HeartbeatRequest from cameleer3-common

Replace local HeartbeatRequest DTO with the shared model from
cameleer3-common. Message types exchanged between server and agent
belong in the common module.

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

cameleer3-server-app/src/main/java/com/cameleer3/server/app/controller/AgentRegistrationController.java

@@ -7,7 +7,7 @@ import com.cameleer3.server.app.dto.AgentRefreshResponse;
 import com.cameleer3.server.app.dto.AgentRegistrationRequest;
 import com.cameleer3.server.app.dto.AgentRegistrationResponse;
 import com.cameleer3.server.app.dto.ErrorResponse;
-import com.cameleer3.server.app.dto.HeartbeatRequest;
+import com.cameleer3.common.model.HeartbeatRequest;
 import com.cameleer3.server.app.security.BootstrapTokenValidator;
 import com.cameleer3.server.core.admin.AuditCategory;
 import com.cameleer3.server.core.admin.AuditResult;
@@ -203,10 +203,10 @@ public class AgentRegistrationController {
             return ResponseEntity.notFound().build();
         }
 
-        if (request != null && request.routeStates() != null && !request.routeStates().isEmpty()) {
+        if (request != null && request.getRouteStates() != null && !request.getRouteStates().isEmpty()) {
             AgentInfo agent = registryService.findById(id);
             if (agent != null) {
-                for (var entry : request.routeStates().entrySet()) {
+                for (var entry : request.getRouteStates().entrySet()) {
                     RouteStateRegistry.RouteState state = parseRouteState(entry.getValue());
                     if (state != null) {
                         routeStateRegistry.setState(agent.applicationId(), entry.getKey(), state);

cameleer3-server-app/src/main/java/com/cameleer3/server/app/dto/HeartbeatRequest.java

@@ -1,7 +0,0 @@
-package com.cameleer3.server.app.dto;
-
-import java.util.Map;
-
-public record HeartbeatRequest(
-    Map<String, String> routeStates
-) {}