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-app/src/test/java/com/cameleer3/server/app/controller/AgentCommandControllerIT.java

@@ -9,7 +9,6 @@ import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.web.client.TestRestTemplate;
 import org.springframework.http.HttpEntity;
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;

cameleer3-server-app/src/test/java/com/cameleer3/server/app/controller/AgentRegistrationControllerIT.java

@@ -9,7 +9,6 @@ import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.web.client.TestRestTemplate;
 import org.springframework.http.HttpEntity;
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;

cameleer3-server-app/src/test/java/com/cameleer3/server/app/controller/AgentSseControllerIT.java

@@ -9,7 +9,6 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.web.client.TestRestTemplate;
 import org.springframework.boot.test.web.server.LocalServerPort;
 import org.springframework.http.HttpEntity;
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.ResponseEntity;
 
 import java.io.BufferedReader;

cameleer3-server-app/src/test/java/com/cameleer3/server/app/controller/ExecutionControllerIT.java

@@ -10,7 +10,6 @@ import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
-import org.springframework.jdbc.core.JdbcTemplate;
 
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.assertj.core.api.Assertions.assertThat;

cameleer3-server-app/src/test/java/com/cameleer3/server/app/security/SecurityFilterIT.java

@@ -27,12 +27,11 @@ class SecurityFilterIT extends AbstractPostgresIT {
     @Autowired
     private TestSecurityHelper securityHelper;
 
-    private String jwt;
     private String viewerJwt;
 
     @BeforeEach
     void setUp() {
-        jwt = securityHelper.registerTestAgent("test-agent-security-filter-it");
+        securityHelper.registerTestAgent("test-agent-security-filter-it");
         viewerJwt = securityHelper.viewerToken();
     }