feat: 请求体规则扩展(append/insert/regex_replace)、OAuth 代理节点支持与列表分页

- 请求体规则新增 append、insert、regex_replace 三种操作，路径语法支持数组索引
- OAuth 授权/导入/批量导入支持指定代理节点(proxy_node_id)，Key 级代理避免 IP 污染
- 密钥列表、模型映射、模型列表添加智能分页(useSmartPagination)
- AdvancedGuide 新增请求体规则使用指南与示例
- 简化 Codex enrich_codex 实现，README 添加 QQ 群二维码

frontend/src/composables/useSmartPagination.ts

@@ -0,0 +1,92 @@
+import { ref, computed, watch, nextTick, type Ref, type ComputedRef } from 'vue'
+
+/**
+ * 智能分页 composable
+ *
+ * 根据列表容器的实际渲染高度自动决定是否分页以及每页条数。
+ * 当列表总高度超过阈值时自动启用分页，低于阈值时恢复全量显示。
+ *
+ * @param items        响应式数据源（全量列表）
+ * @param listRef      列表容器 DOM 引用
+ * @param maxHeight    触发分页的高度阈值（px），默认 500
+ */
+export function useSmartPagination<T>(
+  items: ComputedRef<T[]> | Ref<T[]>,
+  listRef: Ref<HTMLElement | null>,
+  maxHeight = 500,
+) {
+  const currentPage = ref(1)
+  const itemsPerPage = ref(0) // 0 = 不分页
+  const cachedAvgItemHeight = ref(0)
+
+  const shouldPaginate = computed(() => {
+    return itemsPerPage.value > 0 && items.value.length > itemsPerPage.value
+  })
+
+  const paginatedItems = computed(() => {
+    if (!shouldPaginate.value) return items.value
+    const start = (currentPage.value - 1) * itemsPerPage.value
+    return items.value.slice(start, start + itemsPerPage.value)
+  })
+
+  const totalPages = computed(() => {
+    if (!shouldPaginate.value) return 1
+    return Math.ceil(items.value.length / itemsPerPage.value)
+  })
+
+  /** 将当前页内的局部索引转换为全局索引 */
+  function getGlobalIndex(localIdx: number): number {
+    if (!shouldPaginate.value) return localIdx
+    return (currentPage.value - 1) * itemsPerPage.value + localIdx
+  }
+
+  /** 检测是否需要分页并计算每页条数 */
+  function detect() {
+    const el = listRef.value
+    if (!el || items.value.length <= 2) {
+      itemsPerPage.value = 0
+      return
+    }
+
+    const scrollHeight = el.scrollHeight
+    const renderedCount = paginatedItems.value.length
+
+    if (renderedCount > 0 && scrollHeight > 0) {
+      cachedAvgItemHeight.value = scrollHeight / renderedCount
+    }
+
+    const estimatedTotalHeight = cachedAvgItemHeight.value * items.value.length
+    if (estimatedTotalHeight > maxHeight && cachedAvgItemHeight.value > 0) {
+      itemsPerPage.value = Math.max(Math.floor(maxHeight / cachedAvgItemHeight.value), 3)
+      const maxPage = Math.ceil(items.value.length / itemsPerPage.value)
+      if (currentPage.value > maxPage) {
+        currentPage.value = maxPage
+      }
+    } else {
+      itemsPerPage.value = 0
+    }
+  }
+
+  /** 重置分页状态（数据源切换时调用） */
+  function reset() {
+    currentPage.value = 1
+    itemsPerPage.value = 0
+    cachedAvgItemHeight.value = 0
+  }
+
+  // 数据源变化时自动重新检测（immediate 确保首次挂载时也检测）
+  watch(items, () => {
+    currentPage.value = 1
+    nextTick(detect)
+  }, { immediate: true, flush: 'post' })
+
+  return {
+    currentPage,
+    totalPages,
+    shouldPaginate,
+    paginatedItems,
+    getGlobalIndex,
+    detect,
+    reset,
+  }
+}