feat: add Vue2 exercises for dynamic styles, lifecycle methods, component communication, and course management dashboard

- Implement dynamic styles and event handling in Vue2 with a card component.
- Create lifecycle methods exercise to simulate async data loading and instance destruction.
- Develop a component communication exercise with props, events, and slots.
- Build a comprehensive course management dashboard with filtering, statistics, and component interactions.

07-vue2/08-components-communication-and-final/starter.js

@@ -0,0 +1,66 @@
+Vue.component("course-badge", {
+  props: {
+    label: {
+      type: String,
+      default: "默认角标",
+    },
+  },
+  template: `<span style="display:inline-block;margin-bottom:8px;padding:4px 10px;border-radius:999px;background:#eef4ff;color:#2d6cdf;">{{ label }}</span>`,
+});
+
+const CourseCard = {
+  props: {
+    course: {
+      type: Object,
+      required: true,
+    },
+    theme: {
+      type: String,
+      default: "normal",
+      validator(value) {
+        return ["normal", "accent"].includes(value);
+      },
+    },
+  },
+  template: `
+    <article class="card" :style="theme === 'accent' ? 'border-color:#2d6cdf;' : ''">
+      <course-badge :label="course.level"></course-badge>
+      <h2>{{ course.title }}</h2>
+      <p :class="{ done: course.finished }">
+        {{ course.finished ? "已完成" : "学习中" }}
+      </p>
+      <button type="button" @click="$emit('toggle', course.id)">
+        <slot name="action">操作</slot>
+      </button>
+    </article>
+  `,
+};
+
+new Vue({
+  el: "#app",
+  components: {
+    CourseCard,
+  },
+  data: {
+    keyword: "",
+    courses: [
+      { id: 1, title: "Vue 实例", finished: true, level: "基础" },
+      { id: 2, title: "模板语法", finished: false, level: "基础" },
+      { id: 3, title: "组件通信", finished: false, level: "进阶" },
+    ],
+  },
+  computed: {
+    filteredCourses() {
+      // 任务：根据 keyword 过滤课程列表
+      return this.courses;
+    },
+  },
+  methods: {
+    toggleCourse(courseId) {
+      // 任务：根据 courseId 切换 finished
+    },
+    focusInput() {
+      // 任务：通过 ref 聚焦输入框
+    },
+  },
+});