feat(分页): 为每页添加独立的导航配置支持

重构分页逻辑，将导航配置从全局改为每页独立
新增 page_nav_props_by_index 存储每页导航属性
添加 normalizePaginatorProps 方法规范化分页符属性

@@ -15,6 +15,8 @@ export function usePagination(formDataRef, options = {}) {
     const enable_pagination = ref(false)
     // 当前页索引
     const current_page_index = ref(0)
+    // 每一页的导航配置（由相邻的 paginator 控件决定）
+    const page_nav_props_by_index = ref([])
 
     // 过滤后的分页：剔除被隐藏(disabled)的字段，但保留空页占位，确保分页总数与 paginator 一致
     const filtered_pages = computed(() => {
@@ -43,30 +45,62 @@ export function usePagination(formDataRef, options = {}) {
     })
 
     /**
+     * 规范化分页符属性为导航配置
+     * @param {Object} props 分页符的 component_props
+     * @returns {{prev_text: string, next_text: string, prev_disabled: boolean}} 导航配置
+     */
+    const normalizePaginatorProps = (props = {}) => {
+        // 中文文案默认值
+        const nav = { prev_text: '上一页', next_text: '下一页', prev_disabled: false }
+        if (props.back_title) nav.prev_text = props.back_title
+        if (props.next_title) nav.next_text = props.next_title
+        // 是否允许返回：true 允许，false 不允许
+        if (typeof props.is_back === 'boolean') nav.prev_disabled = !props.is_back
+        return nav
+    }
+
+    /**
      * 构建分页分组
-     * @description 优先按 paginator 分组；若仅一组则按固定大小分片
+     * @description 优先按 paginator 分组；并为每一页记录其对应的导航文案与返回策略
      */
     const buildPages = () => {
-        const result = []
+        const pages = []
+        const navs = []
         let cur = []
+        // 当前页导航配置，默认值；当遇到 paginator 时更新为“下一页”的导航
+        let current_nav = normalizePaginatorProps()
         // 连续的 paginator 需要忽略，避免出现空分页
         let last_was_paginator = false
         formDataRef.value.forEach(item => {
             const tag = item.component_props?.tag
-            // 分隔符 paginator 作为分页分组边界
+            // 分隔符 paginator 作为分页分组边界，同时决定后续一页的导航配置
             if (tag === 'paginator') {
-                // 若前一个也是 paginator，则忽略本次（不产生空页）
+                // 连续分页符：忽略后者，保留先前设置，避免空页与属性覆盖
                 if (last_was_paginator) return
-                if (cur.length) result.push(cur)
+                // 如果当前已有内容，先把“这一页”收束，并使用当前导航配置
+                if (cur.length) {
+                    pages.push(cur)
+                    navs.push(current_nav)
                     cur = []
+                }
+                // 更新“下一页”的导航配置为本分页符设置
+                current_nav = normalizePaginatorProps(item.component_props)
                 last_was_paginator = true
                 return
             }
+            // 普通字段加入当前页
             cur.push(item.key)
             last_was_paginator = false
         })
-        if (cur.length) result.push(cur)
-        if (result.length <= 1) {
+
+        // 收尾：最后一页
+        if (cur.length) {
+            pages.push(cur)
+            navs.push(current_nav)
+        }
+
+        // 若未显式分页，仅按固定大小分片，并为每一页设置默认导航
+        if (pages.length <= 1) {
             const size = 8
             const keys = formDataRef.value.filter(i => i.component_props?.tag !== 'paginator').map(i => i.key)
             const chunked = []
@@ -74,8 +108,10 @@ export function usePagination(formDataRef, options = {}) {
                 chunked.push(keys.slice(i, i + size))
             }
             pages_raw.value = chunked.length ? chunked : [keys]
+            page_nav_props_by_index.value = (chunked.length ? chunked : [keys]).map(() => normalizePaginatorProps())
         } else {
-            pages_raw.value = result
+            pages_raw.value = pages
+            page_nav_props_by_index.value = navs
         }
     }
 
@@ -94,26 +130,12 @@ export function usePagination(formDataRef, options = {}) {
 
     /**
      * 分页导航配置
-     * @description 仅从 tag 为 paginator 的字段中读取导航文案与可返回状态
+     * @description 根据当前页索引读取对应的分页符导航文案与返回控制
      * @returns {{prev_text: string, next_text: string, prev_disabled: boolean}}
      */
     const page_nav = computed(() => {
-        // 默认文案与状态
-        let prev_text = '上一页'
-        let next_text = '下一页'
-        let prev_disabled = false
-
-        // 仅查找 tag=paginator 的字段并提取其 component_props
-        const paginator_item = formDataRef.value.find(i => i?.component_props?.tag === 'paginator')
-        if (paginator_item && paginator_item.component_props) {
-            const props = paginator_item.component_props
-            if (props.back_title) prev_text = props.back_title
-            if (props.next_title) next_text = props.next_title
-            // is_back 表示是否允许返回
-            if (typeof props.is_back === 'boolean') prev_disabled = !props.is_back
-        }
-
-        return { prev_text, next_text, prev_disabled }
+        const def = normalizePaginatorProps()
+        return page_nav_props_by_index.value[current_page_index.value] || def
     })
 
     /**