Split multi-hook frontend modules into single-hook files

frontend/src/hooks/useGlobalConfig.ts

@@ -0,0 +1,68 @@
+/**
+ * React hook for loading and updating global configuration.
+ */
+
+import { useCallback, useEffect, useRef, useState } from "react";
+import { fetchGlobalConfig, updateGlobalConfig } from "../api/config";
+import { handleFetchError } from "../utils/fetchError";
+import type { GlobalConfig, GlobalConfigUpdate } from "../types/config";
+
+export interface UseGlobalConfigResult {
+  config: GlobalConfig | null;
+  loading: boolean;
+  error: string | null;
+  refresh: () => void;
+  updateConfig: (update: GlobalConfigUpdate) => Promise<void>;
+}
+
+/**
+ * Load global configuration and expose update operations.
+ */
+export function useGlobalConfig(): UseGlobalConfigResult {
+  const [config, setConfig] = useState<GlobalConfig | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const abortRef = useRef<AbortController | null>(null);
+
+  const load = useCallback((): void => {
+    abortRef.current?.abort();
+    const ctrl = new AbortController();
+    abortRef.current = ctrl;
+    setLoading(true);
+    setError(null);
+
+    fetchGlobalConfig()
+      .then((resp) => {
+        if (!ctrl.signal.aborted) {
+          setConfig(resp);
+        }
+      })
+      .catch((err: unknown) => {
+        if (!ctrl.signal.aborted) {
+          handleFetchError(err, setError, "Failed to fetch global config");
+        }
+      })
+      .finally(() => {
+        if (!abortRef.current?.signal.aborted) {
+          setLoading(false);
+        }
+      });
+  }, []);
+
+  useEffect(() => {
+    load();
+    return (): void => {
+      abortRef.current?.abort();
+    };
+  }, [load]);
+
+  const updateConfig = useCallback(
+    async (update: GlobalConfigUpdate): Promise<void> => {
+      await updateGlobalConfig(update);
+      load();
+    },
+    [load],
+  );
+
+  return { config, loading, error, refresh: load, updateConfig };
+}