fix: 修复企业微信通知环境变量展开问题

- 使用 PAYLOAD=$(cat <<ENDPAYLOAD) 替代 cat > file <<EOF
- 确保环境变量在 heredoc 中正确展开
- 添加测试脚本验证环境变量展开
- 修复构建详情链接和消息内容缺失问题

test-webhook-headers.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+
+echo "=== 测试 Webhook Header 传递 ==="
+echo ""
+
+echo "1. 检查 Forgejo 发送的 Webhook Header..."
+echo ""
+
+echo "2. 创建测试 Webhook 接收器..."
+cat > /tmp/test-webhook.sh << 'EOF'
+#!/bin/bash
+echo "Received webhook at $(date)"
+echo "Headers:"
+for header in "$@"; do
+    echo "  $header"
+done
+echo "Body:"
+cat
+echo ""
+EOF
+
+chmod +x /tmp/test-webhook.sh
+
+echo "3. 测试 Nginx 配置..."
+docker exec novalon-nginx nginx -T 2>&1 | grep -A 20 "location /api/" | head -25
+
+echo ""
+echo "4. 检查最近的 webhook 请求..."
+docker logs woodpecker-server 2>&1 | grep "POST /api/hook" | tail -3
+
+echo ""
+echo "5. 检查 webhook 解析日志..."
+docker logs woodpecker-server 2>&1 | grep "unsupported hook type" | tail -3