fix: resolve 25 SonarQube code smells across 21 files

Remove unused fields (log, rbacService, roleRepository, jwt),
unused variables (agentTps, routeKeys, updated), unused imports
(HttpHeaders, JdbcTemplate). Rename restricted identifier 'record'
to 'auditRecord'/'event'. Return empty collections instead of null.
Replace .collect(Collectors.toList()) with .toList(). Simplify
conditional return in BootstrapTokenValidator.

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

cameleer3-server-core/src/main/java/com/cameleer3/server/core/admin/AuditRepository.java

@@ -5,7 +5,7 @@ import java.util.List;
 
 public interface AuditRepository {
 
-    void insert(AuditRecord record);
+    void insert(AuditRecord auditRecord);
 
     record AuditQuery(
             String username,

cameleer3-server-core/src/main/java/com/cameleer3/server/core/admin/AuditService.java

@@ -30,9 +30,9 @@ public class AuditService {
                     HttpServletRequest request) {
         String ip = request != null ? request.getRemoteAddr() : null;
         String userAgent = request != null ? request.getHeader("User-Agent") : null;
-        AuditRecord record = AuditRecord.create(username, action, category, target, detail, result, ip, userAgent);
+        AuditRecord auditRecord = AuditRecord.create(username, action, category, target, detail, result, ip, userAgent);
 
-        repository.insert(record);
+        repository.insert(auditRecord);
 
         if (request != null) {
             request.setAttribute("audit.logged", true);

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

@@ -13,7 +13,7 @@ import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentLinkedQueue;
-import java.util.stream.Collectors;
+
 
 /**
  * In-memory agent registry managing agent lifecycle, heartbeats, and commands.
@@ -53,7 +53,7 @@ public class AgentRegistryService {
                 List.copyOf(routeIds), Map.copyOf(capabilities),
                 AgentState.LIVE, now, now, null);
 
-        AgentInfo result = agents.compute(id, (key, existing) -> {
+        return agents.compute(id, (key, existing) -> {
             if (existing != null) {
                 // Re-registration: update metadata, reset to LIVE
                 log.info("Agent {} re-registering (was {})", id, existing.state());
@@ -67,8 +67,6 @@ public class AgentRegistryService {
             log.info("Agent {} registered (name={}, application={})", id, name, application);
             return newAgent;
         });
-
-        return result;
     }
 
     /**
@@ -196,7 +194,7 @@ public class AgentRegistryService {
     public List<AgentInfo> findByState(AgentState state) {
         return agents.values().stream()
                 .filter(a -> a.state() == state)
-                .collect(Collectors.toList());
+                .toList();
     }
 
     /**
@@ -205,7 +203,7 @@ public class AgentRegistryService {
     public List<AgentInfo> findByApplication(String application) {
         return agents.values().stream()
                 .filter(a -> application.equals(a.applicationId()))
-                .collect(Collectors.toList());
+                .toList();
     }
 
     /**
@@ -276,7 +274,7 @@ public class AgentRegistryService {
         }
         return queue.stream()
                 .filter(cmd -> cmd.status() == CommandStatus.PENDING)
-                .collect(Collectors.toList());
+                .toList();
     }
 
     /**

cameleer3-server-core/src/main/java/com/cameleer3/server/core/detail/DetailService.java

@@ -29,7 +29,7 @@ public class DetailService {
                     // Prefer the raw processor tree (faithful to agent data) over
                     // flat-record reconstruction (which loses iteration context).
                     List<ProcessorNode> processors = parseProcessorsJson(exec.processorsJson());
-                    if (processors == null) {
+                    if (processors.isEmpty()) {
                         // Fallback for executions ingested before processors_json was added
                         List<ProcessorRecord> records = executionStore.findProcessors(executionId);
                         processors = buildTree(records);
@@ -78,12 +78,12 @@ public class DetailService {
 
     /** Parse the raw processor tree JSON stored alongside the execution. */
     private List<ProcessorNode> parseProcessorsJson(String json) {
-        if (json == null || json.isBlank()) return null;
+        if (json == null || json.isBlank()) return List.of();
         try {
             List<ProcessorExecution> executions = JSON.readValue(json, PROCESSOR_EXEC_LIST);
             return convertProcessors(executions);
         } catch (Exception e) {
-            return null;
+            return List.of();
         }
     }