Add admin system logs UI and API support

Introduce a complete admin System Logs feature: adds frontend components (filters, date picker, active filter chips, rows, detail panel, skeletons, pagination, toolbar, user typeahead, and styles) under src/app/admin/logs/components, plus hooks (useAutoRefreshControl, useLogsUrlState, useUserSearch) and types. Add constants for job labels and log filters, wire URL-driven filters/search/date-range/hasError/user/audiobookQuery with pause-on-interact behavior and page-size options. Update API route (/api/admin/logs) to support the expanded query params and exported where-builder. Update documentation (TABLEOFCONTENTS and admin-dashboard) and add/adjust tests for the new admin logs UI and API behavior.

src/app/admin/logs/hooks/useUserSearch.ts

@@ -0,0 +1,88 @@
+/**
+ * Component: useUserSearch Hook (admin logs user typeahead)
+ * Documentation: documentation/admin-dashboard.md
+ *
+ * Fetch-once-and-cache user directory from /api/admin/users for the user
+ * typeahead in LogsFilters. SWR caches the response for the session so every
+ * keystroke filters in-memory — no per-keystroke network round-trip.
+ *
+ * Assumes installs have <500 users (Zach Resolution #3 — fine for self-hosted).
+ */
+
+'use client';
+
+import { useCallback, useMemo } from 'react';
+import useSWR from 'swr';
+import { authenticatedFetcher } from '@/lib/utils/api';
+
+const USERS_URL = '/api/admin/users';
+const MAX_SUGGESTIONS = 10;
+// One-time-per-session cache: dedupe identical fetches for an hour.
+const DEDUPING_INTERVAL_MS = 60 * 60 * 1000;
+
+export interface UserSearchUser {
+  id: string;
+  plexUsername: string;
+  role: string;
+}
+
+interface UsersApiResponse {
+  users: UserSearchUser[];
+}
+
+export interface UseUserSearchResult {
+  users: UserSearchUser[];
+  filterByQuery: (q: string) => UserSearchUser[];
+  /** Resolve a user by id — handy for chip label rendering. */
+  findUserById: (id: string | null | undefined) => UserSearchUser | undefined;
+  isLoading: boolean;
+  error: Error | null;
+}
+
+export function useUserSearch(): UseUserSearchResult {
+  const { data, error, isLoading } = useSWR<UsersApiResponse>(
+    USERS_URL,
+    authenticatedFetcher,
+    {
+      revalidateOnFocus: false,
+      revalidateIfStale: false,
+      revalidateOnReconnect: false,
+      dedupingInterval: DEDUPING_INTERVAL_MS,
+    }
+  );
+
+  const users = useMemo<UserSearchUser[]>(() => data?.users ?? [], [data]);
+
+  const filterByQuery = useCallback(
+    (q: string): UserSearchUser[] => {
+      if (users.length === 0) return [];
+      const trimmed = q.trim().toLowerCase();
+      if (!trimmed) return users.slice(0, MAX_SUGGESTIONS);
+      const out: UserSearchUser[] = [];
+      for (const u of users) {
+        if (u.plexUsername.toLowerCase().includes(trimmed)) {
+          out.push(u);
+          if (out.length >= MAX_SUGGESTIONS) break;
+        }
+      }
+      return out;
+    },
+    [users]
+  );
+
+  const findUserById = useCallback(
+    (id: string | null | undefined): UserSearchUser | undefined => {
+      if (!id) return undefined;
+      return users.find((u) => u.id === id);
+    },
+    [users]
+  );
+
+  return {
+    users,
+    filterByQuery,
+    findUserById,
+    isLoading,
+    error: (error as Error | null) ?? null,
+  };
+}