ux: 动作收藏按钮从顶部浮窗移到底部，与加入计划并排 + 图标美化

- detail 顶部 favbtn 浮窗(需避让胶囊、丑)移除，改为底部 addbar 内与 CTA 并排的方形按钮
- fc-icon 新增 filled 属性：收藏态实心心形(Lucide 描边图标默认 fill=none，filled=true 时 fill=stroke 变实心)
- 收藏按钮美化：圆角 24rpx 方形 + 发丝边框，未收藏描边(text-2)、已收藏实心(accent)+ accent-soft 底色 + accent-ring 边框 + 点按 scale 反馈
- detail.js 清理 favRight/favTop 胶囊避让逻辑(不再需要)

miniprogram/components/fc-icon/index.js

@@ -29,23 +29,28 @@ Component({
     size: { type: Number, value: 20 },
     // 颜色：可传具体 hex，或 var(--xxx)（自动解析为对应 token 色值）
     color: { type: String, value: '' },
+    // 是否实心填充（如收藏后实心心形）。默认描边
+    filled: { type: Boolean, value: false },
   },
   data: { src: '' },
   observers: {
-    name(n) { this._build(n, this.data.color); },
-    color(c) { this._build(this.data.name, c); },
+    name() { this._build(); },
+    color() { this._build(); },
+    filled() { this._build(); },
   },
   lifetimes: {
-    attached() { this._build(this.data.name, this.data.color); },
+    attached() { this._build(); },
   },
   methods: {
-    _build(name, color) {
+    _build() {
+      const { name, color, filled } = this.data;
       const inner = iconSvg[name];
       if (!inner) { this.setData({ src: '' }); return; }
       const stroke = resolveColor(color);
+      const fill = filled ? stroke : 'none';
       const body = inner.replace(/__C__/g, stroke);
       const svg =
-        '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" ' +
+        '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="' + fill + '" ' +
         'stroke="' + stroke + '" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">' +
         body + '</svg>';
       this.setData({ src: 'data:image/svg+xml,' + encodeURIComponent(svg) });

miniprogram/pages/detail/detail.js

@@ -7,8 +7,6 @@ const auth = require('../../utils/auth');
 Page({
   data: {
     statusBarHeight: 20,
-    favRight: 8,
-    favTop: 20,
     id: '',
     planId: '',
     exercise: null,
@@ -23,18 +21,7 @@ Page({
   onLoad(query) {
     const id = query.id || '';
     const planId = query.planId || '';
-    // 收藏按钮需避让微信右上角胶囊按钮(···◯)：用胶囊实际位置算出安全右/上边距
-    let favRight = 8;
-    let favTop = (app.globalData.statusBarHeight || 20) + 6;
-    try {
-      const menu = wx.getMenuButtonBoundingClientRect();
-      const win = (wx.getWindowInfo && wx.getWindowInfo()) || wx.getSystemInfoSync();
-      if (menu && win) {
-        favRight = Math.max(8, win.windowWidth - menu.left + 8);
-        favTop = menu.top + Math.max(0, (menu.height - 36) / 2);
-      }
-    } catch (e) {}
-    this.setData({ statusBarHeight: app.globalData.statusBarHeight || 20, favRight, favTop, id, planId });
+    this.setData({ statusBarHeight: app.globalData.statusBarHeight || 20, id, planId });
     // 防御：id 缺失直接显示空态，避免请求 /api/exercises/ 导致错乱或 404
     if (!id) {
       this.setData({ loading: false });

miniprogram/pages/detail/detail.wxml

@@ -1,10 +1,6 @@
 <view class="page" wx:if="{{exercise}}">
   <navbar title="{{exercise.displayName || exercise.name}}" show-back />
 
-  <view class="favbtn" style="top: {{favTop}}px; right: {{favRight}}px;" bindtap="onToggleFav">
-    <fc-icon name="heart" size="44" color="{{favorited ? 'var(--accent)' : 'var(--text-3)'}}" />
-  </view>
-
   <view class="hero">
     <image
       wx:if="{{heroSrc && !heroError}}"
@@ -68,8 +64,13 @@
   </view>
 
   <view class="addbar">
+    <view class="addbar__inner">
+      <view class="fav {{favorited ? 'fav--on' : ''}}" hover-class="fav--hover" bindtap="onToggleFav">
+        <fc-icon name="heart" size="40" color="{{favorited ? 'var(--accent)' : 'var(--text-2)'}}" filled="{{favorited}}" />
+      </view>
       <view class="cta" bindtap="onAdd">{{ planId ? '加入该计划' : '加入计划' }}</view>
     </view>
+  </view>
 </view>
 
 <view wx:else class="empty-page">

miniprogram/pages/detail/detail.wxss

@@ -45,24 +45,27 @@
   border-top: 1rpx solid var(--line);
   padding-bottom: calc(20rpx + env(safe-area-inset-bottom));
 }
+.addbar__inner { display: flex; align-items: center; gap: 20rpx; }
 .cta {
+  flex: 1;
   display: flex; align-items: center; justify-content: center;
   background: linear-gradient(135deg, var(--gold) 0%, var(--gold-2) 100%);
   color: var(--accent-on); font-weight: 700; font-size: 32rpx;
-  border-radius: 999rpx; padding: 26rpx;
+  border-radius: 999rpx; height: 92rpx; box-sizing: border-box; padding: 0 24rpx;
 }
+.fav {
+  flex: 0 0 auto;
+  width: 92rpx; height: 92rpx; box-sizing: border-box;
+  border-radius: 24rpx;
+  background: var(--surface);
+  border: 1rpx solid var(--line);
+  display: flex; align-items: center; justify-content: center;
+  transition: background 200ms var(--ease), border-color 200ms var(--ease), transform 120ms var(--ease);
+}
+.fav--on { background: var(--accent-soft); border-color: var(--accent-ring); }
+.fav--hover { transform: scale(0.94); }
 
 .empty-page { min-height: 100vh; background: var(--bg-grad); }
 .topbar { height: 88rpx; display: flex; align-items: center; padding: 0 24rpx; }
 .topbar__back { font-size: 56rpx; color: var(--gold); width: 60rpx; line-height: 1; }
 .empty { color: var(--text-3); font-size: 28rpx; text-align: center; padding: 120rpx 0; }
-
-.favbtn {
-  position: fixed; right: 28rpx; z-index: 60;
-  width: 72rpx; height: 72rpx; border-radius: 999rpx;
-  background: var(--float-bg);
-  backdrop-filter: blur(8px);
-  border: 1rpx solid var(--gold-line);
-  display: flex; align-items: center; justify-content: center;
-  font-size: 44rpx; color: var(--gold-2); line-height: 1;
-}