style: 移除Python文件中的编码声明并优化代码格式

refactor: 重构前端组件和样式，添加AI助手功能

docs: 更新README文档，添加ruff代码检查说明

feat: 新增AI助手相关API和前端组件

chore: 更新.gitignore文件，添加ruff缓存配置

fix: 修复前端布局和设置相关的问题

perf: 优化代码结构和性能，移除冗余代码

test: 更新测试文件，移除编码声明

build: 更新依赖版本，调整requirements.txt

frontend/src/components/ThemeSwitch/index.vue

@@ -0,0 +1,40 @@
+<template>
+  <el-dropdown trigger="click" @command="handleDarkChange">
+    <el-icon :size="20">
+      <component :is="settingsStore.theme === ThemeMode.DARK ? Moon : Sunny" />
+    </el-icon>
+    <template #dropdown>
+      <el-dropdown-menu>
+        <el-dropdown-item
+          v-for="item in theneList"
+          :key="item.value"
+          :command="item.value"
+          :disabled="settingsStore.theme === item.value"
+        >
+          <el-icon>
+            <component :is="item.component" />
+          </el-icon>
+          {{ item.label }}
+        </el-dropdown-item>
+      </el-dropdown-menu>
+    </template>
+  </el-dropdown>
+</template>
+<script setup lang="ts">
+import { useSettingsStore } from "@/store";
+import { ThemeMode } from "@/enums";
+import { Moon, Sunny, Monitor } from "@element-plus/icons-vue";
+
+const { t } = useI18n();
+const settingsStore = useSettingsStore();
+
+const theneList = [
+  { label: t("login.light"), value: ThemeMode.LIGHT, component: Sunny },
+  { label: t("login.dark"), value: ThemeMode.DARK, component: Moon },
+  { label: t("login.auto"), value: ThemeMode.AUTO, component: Monitor },
+];
+
+const handleDarkChange = (theme: ThemeMode) => {
+  settingsStore.updateTheme(theme);
+};
+</script>