fix(plan-card): 计划卡片图标改用 fc-icon 渲染

- plan-card 仍用 {{plan.emoji}} 文本渲染，导致创建计划后显示 person-standing 等字面量
- 改为 require iconName 计算 icon，wxml 使用 <fc-icon> 渲染
- 同步清理 badge/emoji 的字体样式

miniprogram/components/plan-card/index.wxss

@@ -12,13 +12,11 @@
   position: absolute; left: 16rpx; top: 16rpx;
   width: 64rpx; height: 64rpx; border-radius: 18rpx;
   display: flex; align-items: center; justify-content: center;
-  font-size: 38rpx; line-height: 1;
 }
 .pc__top { padding: 28rpx; display: flex; }
 .pc__emoji {
   width: 96rpx; height: 96rpx; border-radius: 24rpx;
   display: flex; align-items: center; justify-content: center;
-  font-size: 52rpx; line-height: 1;
 }
 .pc__body { padding: 18rpx 22rpx 8rpx; }
 .pc__name { font-size: 30rpx; font-weight: 700; }