fix: align payloadCaptureMode default with agent (BOTH, not NONE)

Server defaultConfig() and UI fallbacks returned "NONE" for payload
capture, but the agent defaults to "BOTH". This caused unwanted
reconfiguration when users saved other settings — payload capture
would silently change from the agent's default BOTH to NONE.

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

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

@@ -236,7 +236,7 @@ public class ApplicationConfigController {
         config.setApplicationLogLevel("INFO");
         config.setAgentLogLevel("INFO");
         config.setEngineLevel("REGULAR");
-        config.setPayloadCaptureMode("NONE");
+        config.setPayloadCaptureMode("BOTH");
         return config;
     }
 }

ui/src/pages/Admin/AppConfigDetailPage.tsx

@@ -99,7 +99,7 @@ export default function AppConfigDetailPage() {
         applicationLogLevel: config.applicationLogLevel ?? 'INFO',
         agentLogLevel: config.agentLogLevel ?? 'INFO',
         engineLevel: config.engineLevel ?? 'REGULAR',
-        payloadCaptureMode: config.payloadCaptureMode ?? 'NONE',
+        payloadCaptureMode: config.payloadCaptureMode ?? 'BOTH',
         metricsEnabled: config.metricsEnabled,
         samplingRate: config.samplingRate,
         compressSuccess: config.compressSuccess,
@@ -115,7 +115,7 @@ export default function AppConfigDetailPage() {
       applicationLogLevel: config.applicationLogLevel ?? 'INFO',
       agentLogLevel: config.agentLogLevel ?? 'INFO',
       engineLevel: config.engineLevel ?? 'REGULAR',
-      payloadCaptureMode: config.payloadCaptureMode ?? 'NONE',
+      payloadCaptureMode: config.payloadCaptureMode ?? 'BOTH',
       metricsEnabled: config.metricsEnabled,
       samplingRate: config.samplingRate,
       compressSuccess: config.compressSuccess,

ui/src/pages/AgentHealth/AgentHealth.tsx

@@ -122,7 +122,7 @@ export default function AgentHealth() {
       applicationLogLevel: appConfig.applicationLogLevel ?? 'INFO',
       agentLogLevel: appConfig.agentLogLevel ?? 'INFO',
       engineLevel: appConfig.engineLevel ?? 'REGULAR',
-      payloadCaptureMode: appConfig.payloadCaptureMode ?? 'NONE',
+      payloadCaptureMode: appConfig.payloadCaptureMode ?? 'BOTH',
       metricsEnabled: appConfig.metricsEnabled,
     });
     setConfigEditing(true);
@@ -453,7 +453,7 @@ export default function AgentHealth() {
               </div>
               <div className={styles.configField}>
                 <span className={styles.configLabel}>Payload Capture</span>
-                <Select value={String(configDraft.payloadCaptureMode ?? 'NONE')}
+                <Select value={String(configDraft.payloadCaptureMode ?? 'BOTH')}
                   onChange={(e) => setConfigDraft(d => ({ ...d, payloadCaptureMode: e.target.value }))}
                   options={[
                     { value: 'NONE', label: 'None' },
@@ -503,9 +503,9 @@ export default function AgentHealth() {
               </div>
               <div className={styles.configField}>
                 <span className={styles.configLabel}>Payload Capture</span>
-                <Badge label={appConfig.payloadCaptureMode ?? 'NONE'} color={
-                  (appConfig.payloadCaptureMode ?? 'NONE') === 'BOTH' ? 'running'
-                  : (appConfig.payloadCaptureMode ?? 'NONE') === 'NONE' ? 'auto' : 'warning'
+                <Badge label={appConfig.payloadCaptureMode ?? 'BOTH'} color={
+                  (appConfig.payloadCaptureMode ?? 'BOTH') === 'BOTH' ? 'running'
+                  : (appConfig.payloadCaptureMode ?? 'BOTH') === 'NONE' ? 'auto' : 'warning'
                 } variant="filled" />
               </div>
               <div className={styles.configField}>