feat: 添加小红书Feed评论功能 (#50)

实现通过HTTP GIN API和MCP API发表评论到小红书Feed的功能：
- 新增POST /api/v1/feeds/comment端点
- 新增post_comment_to_feed MCP工具
- 添加PostCommentRequest和PostCommentResponse类型
- 实现PostCommentToFeed服务方法
- 新增CommentFeedAction用于浏览器自动化操作

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <noreply@anthropic.com>

xiaohongshu/comment_feed.go

@@ -0,0 +1,50 @@
+package xiaohongshu
+
+import (
+	"context"
+	"time"
+
+	"github.com/go-rod/rod"
+	"github.com/sirupsen/logrus"
+)
+
+// CommentFeedAction 表示 Feed 评论动作
+type CommentFeedAction struct {
+	page *rod.Page
+}
+
+// NewCommentFeedAction 创建 Feed 评论动作
+func NewCommentFeedAction(page *rod.Page) *CommentFeedAction {
+	return &CommentFeedAction{page: page}
+}
+
+// PostComment 发表评论到 Feed
+func (f *CommentFeedAction) PostComment(ctx context.Context, feedID, xsecToken, content string) error {
+	page := f.page.Context(ctx).Timeout(60 * time.Second)
+
+	// 构建详情页 URL
+	url := makeFeedDetailURL(feedID, xsecToken)
+
+	logrus.Infof("Opening feed detail page: %s", url)
+
+	// 导航到详情页
+	page.MustNavigate(url)
+	page.MustWaitDOMStable()
+
+	time.Sleep(1 * time.Second)
+
+	elem := page.MustElement("div.input-box div.content-edit span")
+	elem.MustClick()
+
+	elem2 := page.MustElement("div.input-box div.content-edit p.content-input")
+	elem2.MustInput(content)
+
+	time.Sleep(1 * time.Second)
+
+	submitButton := page.MustElement("div.bottom button.submit")
+	submitButton.MustClick()
+
+	time.Sleep(1 * time.Second)
+
+	return nil
+}

xiaohongshu/feed_detail.go

@@ -25,7 +25,7 @@ func (f *FeedDetailAction) GetFeedDetail(ctx context.Context, feedID, xsecToken
 	page := f.page.Context(ctx).Timeout(60 * time.Second)
 
 	// 构建详情页 URL
-	url := fmt.Sprintf("https://www.xiaohongshu.com/explore/%s?xsec_token=%s&xsec_source=pc_feed", feedID, xsecToken)
+	url := makeFeedDetailURL(feedID, xsecToken)
 
 	// 导航到详情页
 	page.MustNavigate(url)
@@ -75,3 +75,7 @@ func (f *FeedDetailAction) GetFeedDetail(ctx context.Context, feedID, xsecToken
 		Comments: noteDetail.Comments,
 	}, nil
 }
+
+func makeFeedDetailURL(feedID, xsecToken string) string {
+	return fmt.Sprintf("https://www.xiaohongshu.com/explore/%s?xsec_token=%s&xsec_source=pc_feed", feedID, xsecToken)
+}