Add configurable scheduling, UI health/task indicators, and auto-load map with default filters

crawler/frontend/src/services/healthService.ts

@@ -0,0 +1,74 @@
+// Health check service for backend connectivity
+
+export type HealthStatus = 'checking' | 'healthy' | 'unhealthy';
+
+export interface HealthCheckResult {
+  status: HealthStatus;
+  latencyMs?: number;
+  error?: string;
+}
+
+/**
+ * Check backend health by calling the /api/status endpoint
+ */
+export async function checkBackendHealth(): Promise<HealthCheckResult> {
+  const startTime = performance.now();
+
+  try {
+    const response = await fetch('/api/status', {
+      method: 'GET',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+      // Short timeout for health checks
+      signal: AbortSignal.timeout(5000),
+    });
+
+    const latencyMs = Math.round(performance.now() - startTime);
+
+    if (!response.ok) {
+      return {
+        status: 'unhealthy',
+        latencyMs,
+        error: `HTTP ${response.status}`,
+      };
+    }
+
+    const data = await response.json();
+    if (data.status === 'OK') {
+      return {
+        status: 'healthy',
+        latencyMs,
+      };
+    }
+
+    return {
+      status: 'unhealthy',
+      latencyMs,
+      error: 'Unexpected response',
+    };
+  } catch (error) {
+    const latencyMs = Math.round(performance.now() - startTime);
+
+    if (error instanceof Error) {
+      if (error.name === 'TimeoutError' || error.name === 'AbortError') {
+        return {
+          status: 'unhealthy',
+          latencyMs,
+          error: 'Request timeout',
+        };
+      }
+      return {
+        status: 'unhealthy',
+        latencyMs,
+        error: error.message,
+      };
+    }
+
+    return {
+      status: 'unhealthy',
+      latencyMs,
+      error: 'Connection failed',
+    };
+  }
+}