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/lib/utils/error-handling.ts

@@ -0,0 +1,61 @@
+import {isCancelError} from '@/lib/services/core'
+import {toast} from 'sonner'
+
+/**
+ * 错误处理选项
+ */
+interface HandleContextErrorOptions {
+  /** 是否显示 toast 提示 */
+  showToast?: boolean
+  /** 是否在控制台记录错误 */
+  logError?: boolean
+}
+
+/**
+ * 统一处理 Context 中的错误
+ *
+ * @param error - 捕获的错误对象
+ * @param defaultMessage - 默认错误消息
+ * @param options - 错误处理选项
+ * @returns 标准化的 Error 对象
+ *
+ * @example
+ * ```typescript
+ * try {
+ *   await fetchData()
+ * } catch (error) {
+ *   const errorObject = handleContextError(error, '加载数据失败', {
+ *     showToast: true,
+ *     logError: true
+ *   })
+ *   setError(errorObject)
+ * }
+ * ```
+ */
+export function handleContextError(
+  error: unknown,
+  defaultMessage: string,
+  options: HandleContextErrorOptions = {}
+): Error {
+  const { showToast = false, logError = true } = options
+
+  // 取消的请求不算错误
+  if (isCancelError(error)) {
+    return new Error('请求已取消')
+  }
+
+  const errorMessage = error instanceof Error ? error.message : defaultMessage
+  const errorObject = error instanceof Error ? error : new Error(defaultMessage)
+
+  if (logError) {
+    console.error(defaultMessage, error)
+  }
+
+  if (showToast) {
+    toast.error(defaultMessage, {
+      description: errorMessage
+    })
+  }
+
+  return errorObject
+}