feat(销售时间轴): 添加课程1-4子时间轴并优化健康度显示

添加课程1-4的详细子时间轴组件，展示各课程阶段的转化情况
重构健康度显示逻辑，使用新的CSS类名系统
移除按钮中的SVG图标，调整按钮字体大小

my-vue-app/src/views/secondTop/components/Calendar.vue

@@ -10,21 +10,12 @@
       <h2 class="month-year">{{ currentYear }}年{{ currentMonth + 1 }}月</h2>
       <div class="header-actions">
         <button v-if="!shouldShowFinishCamp()" @click="showCampModal = true" class="camp-btn">
-          <svg viewBox="0 0 24 24" width="16" height="16">
-            <path fill="currentColor" d="M12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm-2 15l-5-5 1.41-1.41L10 14.17l7.59-7.59L19 8l-9 9z"/>
-          </svg>
           设置营期
         </button>
         <button v-if="shouldShowFinishCamp()" @click="finishCamp" class="camp-btn finish-camp">
-          <svg viewBox="0 0 24 24" width="16" height="16">
-            <path fill="currentColor" d="M9 16.2L4.8 12l-1.4 1.4L9 19 21 7l-1.4-1.4L9 16.2z"/>
-          </svg>
           结束营期
         </button>
         <button v-if="!isViewingHistory" @click="showHistory" class="history-btn">
-          <svg viewBox="0 0 24 24" width="16" height="16">
-            <path fill="currentColor" d="M13,3A9,9 0 0,0 4,12H1L4.89,15.89L4.96,16.03L9,12H6A7,7 0 0,1 13,5A7,7 0 0,1 20,12A7,7 0 0,1 13,19C11.07,19 9.32,18.21 8.06,16.94L6.64,18.36C8.27,20 10.5,21 13,21A9,9 0 0,0 22,12A9,9 0 0,0 13,3Z"/>
-          </svg>
           历史
         </button>
         <button v-if="isViewingHistory" @click="returnToCurrentPeriod" class="current-btn">
@@ -1452,7 +1443,7 @@ onMounted(async () => {
   color: white;
   border: none;
   border-radius: 6px;
-  font-size: 14px;
+  font-size: 12px;
   font-weight: 500;
   cursor: pointer;
   transition: all 0.2s ease;