feat: 海报生成功能+推广优化

1. 阅读页：
   - 添加"生成海报"和"分享给好友"按钮
   - 海报包含章节摘要+邀请码+小程序码占位
   - 优化推广提示区域，添加推广中心入口

2. 分销中心：
   - 完善海报生成功能（推广海报）
   - 去掉"更多分享方式"，改为"复制朋友圈文案"
   - 添加"分享给好友"小程序卡片按钮

3. 分享链接自动带分销ID

miniprogram/pages/read/read.js

@@ -47,7 +47,9 @@ Page({
     // 弹窗
     showShareModal: false,
     showLoginModal: false,
+    showPosterModal: false,
     isPaying: false,
+    isGeneratingPoster: false,
     
     // 免费章节
     freeIds: ['preface', 'epilogue', '1.1', 'appendix-1', 'appendix-2', 'appendix-3']
@@ -530,6 +532,160 @@ Page({
     wx.navigateTo({ url: '/pages/referral/referral' })
   },
 
+  // 生成海报
+  async generatePoster() {
+    wx.showLoading({ title: '生成中...' })
+    this.setData({ showPosterModal: true, isGeneratingPoster: true })
+    
+    try {
+      const ctx = wx.createCanvasContext('posterCanvas', this)
+      const { section, contentParagraphs } = this.data
+      const userInfo = app.globalData.userInfo
+      const referralCode = userInfo?.referralCode || 'SOUL'
+      
+      // 海报尺寸 300x450
+      const width = 300
+      const height = 450
+      
+      // 背景渐变
+      const grd = ctx.createLinearGradient(0, 0, 0, height)
+      grd.addColorStop(0, '#1a1a2e')
+      grd.addColorStop(1, '#16213e')
+      ctx.setFillStyle(grd)
+      ctx.fillRect(0, 0, width, height)
+      
+      // 顶部装饰条
+      ctx.setFillStyle('#00CED1')
+      ctx.fillRect(0, 0, width, 4)
+      
+      // 标题区域
+      ctx.setFillStyle('#ffffff')
+      ctx.setFontSize(14)
+      ctx.fillText('📚 Soul创业派对', 20, 35)
+      
+      // 章节标题
+      ctx.setFontSize(18)
+      ctx.setFillStyle('#ffffff')
+      const title = section?.title || '精彩内容'
+      const titleLines = this.wrapText(ctx, title, width - 40, 18)
+      let y = 70
+      titleLines.forEach(line => {
+        ctx.fillText(line, 20, y)
+        y += 26
+      })
+      
+      // 分隔线
+      ctx.setStrokeStyle('rgba(255,255,255,0.1)')
+      ctx.beginPath()
+      ctx.moveTo(20, y + 10)
+      ctx.lineTo(width - 20, y + 10)
+      ctx.stroke()
+      
+      // 内容摘要
+      ctx.setFontSize(12)
+      ctx.setFillStyle('rgba(255,255,255,0.8)')
+      y += 30
+      const summary = contentParagraphs.slice(0, 3).join(' ').slice(0, 150) + '...'
+      const summaryLines = this.wrapText(ctx, summary, width - 40, 12)
+      summaryLines.slice(0, 6).forEach(line => {
+        ctx.fillText(line, 20, y)
+        y += 20
+      })
+      
+      // 底部区域背景
+      ctx.setFillStyle('rgba(0,206,209,0.1)')
+      ctx.fillRect(0, height - 120, width, 120)
+      
+      // 小程序码占位（实际需要获取小程序码图片）
+      ctx.setFillStyle('#ffffff')
+      ctx.beginPath()
+      ctx.arc(width - 55, height - 60, 35, 0, Math.PI * 2)
+      ctx.fill()
+      ctx.setFillStyle('#00CED1')
+      ctx.setFontSize(10)
+      ctx.fillText('扫码阅读', width - 72, height - 58)
+      
+      // 邀请信息
+      ctx.setFillStyle('#ffffff')
+      ctx.setFontSize(12)
+      ctx.fillText('长按识别 · 阅读全文', 20, height - 70)
+      ctx.setFillStyle('#FFD700')
+      ctx.setFontSize(11)
+      ctx.fillText(`邀请码: ${referralCode}`, 20, height - 50)
+      ctx.setFillStyle('rgba(255,255,255,0.6)')
+      ctx.setFontSize(10)
+      ctx.fillText('好友购买你获90%收益', 20, height - 32)
+      
+      ctx.draw(true, () => {
+        wx.hideLoading()
+        this.setData({ isGeneratingPoster: false })
+      })
+    } catch (e) {
+      console.error('生成海报失败:', e)
+      wx.hideLoading()
+      wx.showToast({ title: '生成失败', icon: 'none' })
+      this.setData({ showPosterModal: false, isGeneratingPoster: false })
+    }
+  },
+  
+  // 文字换行处理
+  wrapText(ctx, text, maxWidth, fontSize) {
+    const lines = []
+    let line = ''
+    for (let i = 0; i < text.length; i++) {
+      const testLine = line + text[i]
+      const metrics = ctx.measureText(testLine)
+      if (metrics.width > maxWidth && line) {
+        lines.push(line)
+        line = text[i]
+      } else {
+        line = testLine
+      }
+    }
+    if (line) lines.push(line)
+    return lines
+  },
+  
+  // 关闭海报弹窗
+  closePosterModal() {
+    this.setData({ showPosterModal: false })
+  },
+  
+  // 保存海报到相册
+  savePoster() {
+    wx.canvasToTempFilePath({
+      canvasId: 'posterCanvas',
+      success: (res) => {
+        wx.saveImageToPhotosAlbum({
+          filePath: res.tempFilePath,
+          success: () => {
+            wx.showToast({ title: '已保存到相册', icon: 'success' })
+            this.setData({ showPosterModal: false })
+          },
+          fail: (err) => {
+            if (err.errMsg.includes('auth deny')) {
+              wx.showModal({
+                title: '提示',
+                content: '需要相册权限才能保存海报',
+                confirmText: '去设置',
+                success: (res) => {
+                  if (res.confirm) {
+                    wx.openSetting()
+                  }
+                }
+              })
+            } else {
+              wx.showToast({ title: '保存失败', icon: 'none' })
+            }
+          }
+        })
+      },
+      fail: () => {
+        wx.showToast({ title: '生成图片失败', icon: 'none' })
+      }
+    }, this)
+  },
+
   // 阻止冒泡
   stopPropagation() {}
 })

miniprogram/pages/read/read.wxml

@@ -80,13 +80,37 @@
           </view>
         </view>
 
-        <!-- 推广提示 -->
-        <view class="share-tip" bindtap="showShare">
-          <view class="tip-content">
-            <text class="tip-title">推荐好友，共同成长</text>
-            <text class="tip-desc">邀请好友加入，享90%推广收益</text>
+        <!-- 分享操作区 -->
+        <view class="action-section">
+          <view class="action-header">
+            <text class="action-title">分享这篇内容</text>
+          </view>
+          <view class="action-buttons">
+            <button class="action-btn btn-share" open-type="share">
+              <text class="action-icon">💬</text>
+              <text class="action-text">分享给好友</text>
+            </button>
+            <view class="action-btn btn-poster" bindtap="generatePoster">
+              <text class="action-icon">🖼️</text>
+              <text class="action-text">生成海报</text>
+            </view>
+          </view>
+        </view>
+
+        <!-- 推广提示 -->
+        <view class="promo-section">
+          <view class="promo-card" bindtap="goToReferral">
+            <view class="promo-left">
+              <view class="promo-icon">💰</view>
+              <view class="promo-info">
+                <text class="promo-title">推荐好友，共同成长</text>
+                <text class="promo-desc">邀请好友购买，享90%推广收益</text>
+              </view>
+            </view>
+            <view class="promo-right">
+              <text class="promo-arrow">→</text>
+            </view>
           </view>
-          <view class="tip-btn">立即推广</view>
         </view>
       </view>
     </view>
@@ -171,34 +195,27 @@
     </view>
   </view>
 
-  <!-- 分享弹窗 -->
-  <view class="modal-overlay" wx:if="{{showShareModal}}" bindtap="closeShareModal">
-    <view class="modal-content share-modal" catchtap="stopPropagation">
+  <!-- 海报生成弹窗 -->
+  <view class="modal-overlay" wx:if="{{showPosterModal}}" bindtap="closePosterModal">
+    <view class="modal-content poster-modal" catchtap="stopPropagation">
       <view class="modal-header">
-        <text class="modal-title">分享文章</text>
-        <view class="modal-close" bindtap="closeShareModal">✕</view>
+        <text class="modal-title">生成海报</text>
+        <view class="modal-close" bindtap="closePosterModal">✕</view>
       </view>
 
-      <view class="share-link-box">
-        <text class="link-label">你的专属分享链接</text>
-        <text class="link-url">https://soul.quwanzhi.com/read/{{sectionId}}</text>
-        <text class="link-tip">邀请码: 好友购买你获得90%佣金</text>
+      <!-- 海报预览 -->
+      <view class="poster-preview">
+        <canvas canvas-id="posterCanvas" class="poster-canvas" style="width: 300px; height: 450px;"></canvas>
       </view>
 
-      <view class="share-buttons">
-        <view class="share-btn" bindtap="copyLink">
-          <view class="share-btn-icon icon-copy">📋</view>
-          <text class="share-btn-text">复制链接</text>
-        </view>
-        <button class="share-btn" open-type="share">
-          <view class="share-btn-icon icon-wechat">微</view>
-          <text class="share-btn-text">微信好友</text>
-        </button>
-        <view class="share-btn" bindtap="goToReferral">
-          <view class="share-btn-icon icon-poster">🖼️</view>
-          <text class="share-btn-text">生成海报</text>
+      <view class="poster-actions">
+        <view class="poster-btn btn-save" bindtap="savePoster">
+          <text class="btn-icon">💾</text>
+          <text>保存到相册</text>
         </view>
       </view>
+
+      <text class="poster-tip">长按海报可直接分享到微信</text>
     </view>
   </view>
 

miniprogram/pages/read/read.wxss

@@ -396,42 +396,123 @@
   color: rgba(255, 255, 255, 0.6);
 }
 
-/* ===== 分享提示 ===== */
-.share-tip {
+/* ===== 分享操作区 ===== */
+.action-section {
+  margin-top: 64rpx;
+  padding: 32rpx;
+  background: rgba(255, 255, 255, 0.03);
+  border-radius: 24rpx;
+  border: 2rpx solid rgba(255, 255, 255, 0.05);
+}
+
+.action-header {
+  margin-bottom: 24rpx;
+}
+
+.action-title {
+  font-size: 28rpx;
+  color: rgba(255, 255, 255, 0.6);
+}
+
+.action-buttons {
+  display: flex;
+  gap: 24rpx;
+}
+
+.action-btn {
+  flex: 1;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 12rpx;
+  padding: 28rpx 24rpx;
+  border-radius: 20rpx;
+  border: none;
+  background: transparent;
+  line-height: normal;
+}
+
+.action-btn::after {
+  border: none;
+}
+
+.btn-share {
+  background: rgba(7, 193, 96, 0.15);
+  border: 2rpx solid rgba(7, 193, 96, 0.3);
+}
+
+.btn-poster {
+  background: rgba(255, 215, 0, 0.15);
+  border: 2rpx solid rgba(255, 215, 0, 0.3);
+}
+
+.action-icon {
+  font-size: 36rpx;
+}
+
+.action-text {
+  font-size: 28rpx;
+  color: #ffffff;
+  font-weight: 500;
+}
+
+/* ===== 推广提示区 ===== */
+.promo-section {
+  margin-top: 32rpx;
+}
+
+.promo-card {
   display: flex;
   align-items: center;
   justify-content: space-between;
   padding: 32rpx;
-  background: linear-gradient(90deg, rgba(255, 215, 0, 0.1) 0%, transparent 100%);
+  background: linear-gradient(135deg, rgba(255, 215, 0, 0.1) 0%, rgba(255, 165, 0, 0.05) 100%);
   border: 2rpx solid rgba(255, 215, 0, 0.2);
   border-radius: 24rpx;
 }
 
-.tip-content {
+.promo-left {
+  display: flex;
+  align-items: center;
+  gap: 20rpx;
+}
+
+.promo-icon {
+  width: 80rpx;
+  height: 80rpx;
+  background: rgba(255, 215, 0, 0.2);
+  border-radius: 50%;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  font-size: 36rpx;
+}
+
+.promo-info {
   flex: 1;
 }
 
-.tip-title {
-  font-size: 28rpx;
+.promo-title {
+  font-size: 30rpx;
   color: #ffffff;
-  font-weight: 500;
+  font-weight: 600;
   display: block;
 }
 
-.tip-desc {
+.promo-desc {
   font-size: 24rpx;
-  color: rgba(255, 255, 255, 0.6);
+  color: rgba(255, 255, 255, 0.5);
   display: block;
   margin-top: 8rpx;
 }
 
-.tip-btn {
-  padding: 16rpx 32rpx;
-  background: #FFD700;
-  color: #000000;
-  font-size: 28rpx;
-  font-weight: 500;
-  border-radius: 16rpx;
+.promo-right {
+  padding-left: 20rpx;
+}
+
+.promo-arrow {
+  font-size: 32rpx;
+  color: #FFD700;
 }
 
 /* ===== 弹窗 ===== */
@@ -792,3 +873,56 @@
   font-size: 28rpx;
   color: rgba(255, 255, 255, 0.8);
 }
+
+/* ===== 海报弹窗 ===== */
+.poster-modal {
+  padding-bottom: calc(64rpx + env(safe-area-inset-bottom));
+}
+
+.poster-preview {
+  display: flex;
+  justify-content: center;
+  margin: 32rpx 0;
+  padding: 24rpx;
+  background: rgba(0, 0, 0, 0.3);
+  border-radius: 24rpx;
+}
+
+.poster-canvas {
+  border-radius: 16rpx;
+  box-shadow: 0 16rpx 48rpx rgba(0, 0, 0, 0.5);
+}
+
+.poster-actions {
+  display: flex;
+  gap: 24rpx;
+  margin-bottom: 24rpx;
+}
+
+.poster-btn {
+  flex: 1;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 12rpx;
+  padding: 28rpx;
+  border-radius: 24rpx;
+  font-size: 30rpx;
+  font-weight: 500;
+}
+
+.btn-save {
+  background: linear-gradient(135deg, #00CED1 0%, #20B2AA 100%);
+  color: #ffffff;
+}
+
+.btn-icon {
+  font-size: 32rpx;
+}
+
+.poster-tip {
+  font-size: 24rpx;
+  color: rgba(255, 255, 255, 0.4);
+  text-align: center;
+  display: block;
+}