Add React UI with Execution Explorer, auth, and standalone deployment

- Scaffold Vite + React + TypeScript frontend in ui/ with full design
  system (dark/light themes) matching the HTML mockups
- Implement Execution Explorer page: search filters, results table with
  expandable processor tree and exchange detail sidebar, pagination
- Add UI authentication: UiAuthController (login/refresh endpoints),
  JWT filter handles ui: subject prefix, CORS configuration
- Shared components: StatusPill, DurationBar, StatCard, AppBadge,
  FilterChip, Pagination — all using CSS Modules with design tokens
- API client layer: openapi-fetch with auth middleware, TanStack Query
  hooks for search/detail/snapshot queries, Zustand for state
- Standalone deployment: Nginx Dockerfile, K8s Deployment + ConfigMap +
  NodePort (30080), runtime config.js for API base URL
- Embedded mode: maven-resources-plugin copies ui/dist into JAR static
  resources, SPA forward controller for client-side routing
- CI/CD: UI build step, Docker build/push for server-ui image, K8s
  deploy step for UI, UI credential secrets

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui/src/auth/use-auth.ts

@@ -0,0 +1,45 @@
+import { useEffect } from 'react';
+import { useAuthStore } from './auth-store';
+import { configureAuth } from '../api/client';
+import { useNavigate } from 'react-router';
+
+export function useAuth() {
+  const { accessToken, isAuthenticated, refresh, logout } = useAuthStore();
+  const navigate = useNavigate();
+
+  // Wire API client to auth store
+  useEffect(() => {
+    configureAuth({
+      getAccessToken: () => useAuthStore.getState().accessToken,
+      onUnauthorized: async () => {
+        const ok = await useAuthStore.getState().refresh();
+        if (!ok) {
+          useAuthStore.getState().logout();
+          navigate('/login', { replace: true });
+        }
+      },
+    });
+  }, [navigate]);
+
+  // Auto-refresh: check token expiry every 30s
+  useEffect(() => {
+    if (!isAuthenticated) return;
+    const interval = setInterval(async () => {
+      const token = useAuthStore.getState().accessToken;
+      if (!token) return;
+      try {
+        const payload = JSON.parse(atob(token.split('.')[1]));
+        const expiresIn = payload.exp * 1000 - Date.now();
+        // Refresh when less than 5 minutes remaining
+        if (expiresIn < 5 * 60 * 1000) {
+          await refresh();
+        }
+      } catch {
+        // Token parse failure — ignore, will fail on next API call
+      }
+    }, 30_000);
+    return () => clearInterval(interval);
+  }, [isAuthenticated, refresh]);
+
+  return { accessToken, isAuthenticated, logout };
+}