refactor: extract duplicated utility functions into shared modules

Consolidate 20+ duplicate function definitions across UI components into
three shared util files (format-utils, agent-utils, config-draft-utils).

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

ui/src/pages/Admin/AppConfigDetailPage.tsx

@@ -9,6 +9,7 @@ import { useApplicationConfig, useUpdateApplicationConfig } from '../../api/quer
 import type { ApplicationConfig, TapDefinition, ConfigUpdateResponse } from '../../api/queries/commands';
 import { useCatalog } from '../../api/queries/catalog';
 import type { CatalogApp, CatalogRoute } from '../../api/queries/catalog';
+import { applyTracedProcessorUpdate, applyRouteRecordingUpdate } from '../../utils/config-draft-utils';
 import styles from './AppConfigDetailPage.module.css';
 
 type BadgeColor = 'primary' | 'success' | 'warning' | 'error' | 'running' | 'auto';
@@ -130,18 +131,11 @@ export default function AppConfigDetailPage() {
   }
 
   function updateTracedProcessor(processorId: string, mode: string) {
-    setTracedDraft((prev) => {
-      if (mode === 'REMOVE') {
-        const next = { ...prev };
-        delete next[processorId];
-        return next;
-      }
-      return { ...prev, [processorId]: mode };
-    });
+    setTracedDraft((prev) => applyTracedProcessorUpdate(prev, processorId, mode));
   }
 
   function updateRouteRecording(routeId: string, recording: boolean) {
-    setRouteRecordingDraft((prev) => ({ ...prev, [routeId]: recording }));
+    setRouteRecordingDraft((prev) => applyRouteRecordingUpdate(prev, routeId, recording));
   }
 
   function handleSave() {