feat: 实现功能&优化

- 底部播放栏
- MediaSession
- 插件系统&存储位置
- URL缓存机制
- 整理项目结构

src/renderer/layout/MainLayout.vue

@@ -0,0 +1,99 @@
+<template>
+  <div class="main-layout" :class="{ 'has-player': hasSongs }">
+    <Sidebar class="layout-sidebar" />
+    <main class="content-area">
+      <TopBar />
+      <div class="page-content">
+        <router-view v-slot="{ Component }">
+          <transition name="fade" mode="out-in">
+            <component :is="Component" />
+          </transition>
+        </router-view>
+      </div>
+    </main>
+    <PlayerBar />
+  </div>
+</template>
+
+<script setup lang="ts">
+import { computed } from 'vue';
+import Sidebar from '../components/Sidebar.vue';
+import TopBar from '../components/TopBar.vue';
+import PlayerBar from '../components/PlayerBar.vue';
+import { usePlayerStore } from '../stores/player.ts';
+
+const playerStore = usePlayerStore();
+const hasSongs = computed(() => playerStore.playlist.length > 0);
+</script>
+
+<style>
+/* 关键修复：全局重置盒模型 */
+/* 这确保 width: 100% + padding 不会撑破容器 */
+*, *::before, *::after {
+  box-sizing: border-box;
+  margin: 0;
+  padding: 0;
+}
+
+/* 隐藏 body 的滚动条，防止整体页面出现原生滚动条 */
+body {
+  overflow: hidden;
+}
+</style>
+
+<style scoped>
+.main-layout {
+  display: flex;
+  height: 100vh;
+  width: 100vw;
+  background-color: var(--color-bg-primary);
+  overflow: hidden; /* 确保整个应用不会出现双重滚动条 */
+}
+
+/* Dynamic Spacing for PlayerBar */
+.layout-sidebar,
+.content-area {
+  transition: padding-bottom 0.3s ease;
+}
+
+.main-layout.has-player .layout-sidebar,
+.main-layout.has-player .content-area {
+  padding-bottom: 80px; /* PlayerBar Height */
+}
+
+.content-area {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  position: relative;
+  overflow: hidden;
+  /* 关键修复：防止 flex 子项内容过宽撑开容器 */
+  min-width: 0;
+}
+
+.page-content {
+  flex: 1;
+  overflow-y: auto; /* 只允许内容区域滚动 */
+  padding: 0;
+  background-color: var(--color-bg-primary);
+  position: relative;
+}
+
+/* 滚动条样式优化 */
+.page-content::-webkit-scrollbar {
+  width: 8px;
+}
+
+.page-content::-webkit-scrollbar-track {
+  background: transparent;
+}
+
+.page-content::-webkit-scrollbar-thumb {
+  background: var(--color-border-light);
+  border-radius: 4px;
+}
+
+.page-content::-webkit-scrollbar-thumb:hover {
+  background: var(--color-text-muted);
+}
+</style>