refactor(repo): consolidate openflare-server to root and move subprojects to internal/apps

- Merge all files inside openflare-server to the repository root directory.
- Relocate agent, relay, and flared subprojects from internal/ to internal/apps/.
- Combine docker-compose files and update build context paths to root.
- Update GitHub workflows and Dockerfiles to refer to new directories and package names.
- Rewrite Go package imports across all files.
- Resolve database renew test race condition and clean up docs.

frontend/contexts/admin-context.tsx

@@ -0,0 +1,115 @@
+"use client"
+
+import * as React from "react"
+import {createContext, useCallback, useContext, useRef, useState} from "react"
+import {useQueryClient} from "@tanstack/react-query"
+
+import type {SystemConfig, UpdateSystemConfigRequest} from "@/lib/services/admin"
+import services from "@/lib/services"
+import {handleContextError} from "@/lib/utils/error-handling"
+
+
+/** Admin 上下文状态接口 */
+export interface AdminContextState {
+  systemConfigs: SystemConfig[]
+  systemConfigsLoading: boolean
+  systemConfigsError: Error | null
+  refetchSystemConfigs: (type?: 'system' | 'business') => Promise<void>
+  updateSystemConfig: (key: string, data: UpdateSystemConfigRequest) => Promise<void>
+}
+
+const AdminContext = createContext<AdminContextState | null>(null)
+
+/**
+ * Admin Provider
+ * 提供 admin 相关的数据状态管理
+ *
+ * @example
+ * ```tsx
+ * <AdminProvider>
+ *   <div>内容</div>
+ * </AdminProvider>
+ * ```
+ * @param {React.ReactNode} children - Admin Provider 的子元素
+ */
+export function AdminProvider({ children }: { children: React.ReactNode }) {
+  const queryClient = useQueryClient()
+  const [systemConfigs, setSystemConfigs] = useState<SystemConfig[]>([])
+  const [systemConfigsLoading, setSystemConfigsLoading] = useState(false)
+  const [systemConfigsError, setSystemConfigsError] = useState<Error | null>(null)
+
+  const systemRequestIdRef = useRef(0)
+  const lastConfigTypeRef = useRef<'system' | 'business' | undefined>(undefined)
+
+  /** 获取系统配置列表 */
+  const refetchSystemConfigs = useCallback(async (type?: 'system' | 'business') => {
+    lastConfigTypeRef.current = type
+    const requestId = ++systemRequestIdRef.current
+
+    try {
+      setSystemConfigsLoading(true)
+      setSystemConfigsError(null)
+      const data = await services.adminSystemConfig.listSystemConfigs(type)
+
+      if (requestId !== systemRequestIdRef.current) {
+        return
+      }
+
+      setSystemConfigs(data)
+      setSystemConfigsLoading(false)
+    } catch (error) {
+      if (requestId !== systemRequestIdRef.current) {
+        return
+      }
+
+      const errorObject = handleContextError(error, '加载系统配置失败', { logError: true })
+      setSystemConfigsError(errorObject)
+      setSystemConfigsLoading(false)
+    }
+  }, [])
+
+  /** 更新系统配置 */
+  const updateSystemConfig = useCallback(async (key: string, data: UpdateSystemConfigRequest) => {
+    try {
+      await services.adminSystemConfig.updateSystemConfig(key, data)
+      await queryClient.invalidateQueries({ queryKey: ['public-config'] })
+      await refetchSystemConfigs(lastConfigTypeRef.current)
+    } catch (error) {
+      handleContextError(error, '更新系统配置失败')
+      throw error
+    }
+  }, [queryClient, refetchSystemConfigs])
+
+  const value: AdminContextState = {
+    systemConfigs,
+    systemConfigsLoading,
+    systemConfigsError,
+    refetchSystemConfigs,
+    updateSystemConfig,
+  }
+
+  return (
+    <AdminContext.Provider value={value}>
+      {children}
+    </AdminContext.Provider>
+  )
+}
+
+/**
+ * 使用 Admin 上下文
+ *
+ * @example
+ * ```tsx
+ * const { systemConfigs } = useAdmin()
+ * ```
+ * @returns {AdminContextState} Admin 上下文状态
+ */
+export function useAdmin() {
+  const context = useContext(AdminContext)
+
+  if (!context) {
+    throw new Error('useAdmin 必须在 AdminProvider 内部使用')
+  }
+
+  return context
+}