feat: restore agent capabilities from heartbeat after server restart

The heartbeat now carries capabilities (per protocol v2 update).
On each heartbeat, capabilities are updated in the agent registry.
On auto-heal (server restart), capabilities from the heartbeat
are used instead of empty Map.of(), so the agent's feature flags
(replay, routeControl, logForwarding, etc.) are restored
immediately on the first heartbeat.

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

@@ -201,15 +201,17 @@ public class AgentRegistrationController {
     public ResponseEntity<Void> heartbeat(@PathVariable String id,
                                            @RequestBody(required = false) HeartbeatRequest request,
                                            HttpServletRequest httpRequest) {
-        boolean found = registryService.heartbeat(id);
+        Map<String, Object> capabilities = request != null ? request.getCapabilities() : null;
+        boolean found = registryService.heartbeat(id, capabilities);
         if (!found) {
             // Auto-heal: re-register agent from JWT claims after server restart
             var jwtResult = (JwtService.JwtValidationResult) httpRequest.getAttribute(
                     JwtAuthenticationFilter.JWT_RESULT_ATTR);
             if (jwtResult != null) {
                 String application = jwtResult.application() != null ? jwtResult.application() : "default";
+                Map<String, Object> caps = capabilities != null ? capabilities : Map.of();
                 registryService.register(id, id, application, "unknown",
-                        List.of(), Map.of());
+                        List.of(), caps);
                 registryService.heartbeat(id);
                 log.info("Auto-registered agent {} (app={}) from heartbeat after server restart", id, application);
             } else {

cameleer3-server-core/src/main/java/com/cameleer3/server/core/agent/AgentInfo.java

@@ -55,6 +55,11 @@ public record AgentInfo(
                 state, registeredAt, lastHeartbeat, newStaleTransitionTime);
     }
 
+    public AgentInfo withCapabilities(Map<String, Object> newCapabilities) {
+        return new AgentInfo(instanceId, displayName, applicationId, version, routeIds, newCapabilities,
+                state, registeredAt, lastHeartbeat, staleTransitionTime);
+    }
+
     public AgentInfo withMetadata(String displayName, String applicationId, String version,
                                    List<String> routeIds, Map<String, Object> capabilities) {
         return new AgentInfo(instanceId, displayName, applicationId, version, routeIds, capabilities,

cameleer3-server-core/src/main/java/com/cameleer3/server/core/agent/AgentRegistryService.java

@@ -71,14 +71,17 @@ public class AgentRegistryService {
 
     /**
      * Process a heartbeat from an agent.
-     * Updates lastHeartbeat and transitions STALE agents back to LIVE.
+     * Updates lastHeartbeat, capabilities (if provided), and transitions STALE agents back to LIVE.
      *
      * @return true if the agent is known, false otherwise
      */
-    public boolean heartbeat(String id) {
+    public boolean heartbeat(String id, Map<String, Object> capabilities) {
         AgentInfo updated = agents.computeIfPresent(id, (key, existing) -> {
             Instant now = Instant.now();
             AgentInfo result = existing.withLastHeartbeat(now);
+            if (capabilities != null && !capabilities.isEmpty()) {
+                result = result.withCapabilities(Map.copyOf(capabilities));
+            }
             if (existing.state() == AgentState.STALE) {
                 result = result.withState(AgentState.LIVE).withStaleTransitionTime(null);
                 log.info("Agent {} revived from STALE to LIVE via heartbeat", id);
@@ -88,6 +91,11 @@ public class AgentRegistryService {
         return updated != null;
     }
 
+    /** Overload for callers without capabilities (backward compatibility). */
+    public boolean heartbeat(String id) {
+        return heartbeat(id, null);
+    }
+
     /**
      * Manually transition an agent to a new state.
      * Sets staleTransitionTime when transitioning to STALE.