feat(component): 添加后退按钮组件并应用到多个页面

- 新增 BackButton 组件，用于实现后退功能
- 在 agent、knowledge、intelligent-agent 等模块的多个页面中集成后退按钮
- 优化后退按钮的样式和交互效果

src/components/BackButton/backButton.vue

@@ -0,0 +1,38 @@
+<template>
+  <el-button
+    size="medium"
+    class="hover-button mb10"
+    @click="$router.history.go(-1)"
+    icon="el-icon-arrow-left"
+    >返回</el-button
+  >
+</template>
+<script>
+export default {
+  name: 'backButton',
+  data() {
+    return {}
+  },
+  props: {},
+  watch: {},
+  components: {},
+  filters: {},
+  methods: {},
+  created() {},
+  mounted() {},
+  computed: {}
+}
+</script>
+<style scoped lang="scss">
+@import '@/assets/sass/renderSass/theme.scss';
+.hover-button {
+  border: none !important;
+  padding: 8px 2px;
+  &:hover {
+    background: $--color-primary-button-gradient;
+    color: #fff;
+    padding: 8px 15px;
+    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.12);
+  }
+}
+</style>