feat: enhance feed detail functionality with MCP interface improvements (#45)

* feat: add feed detail page functionality with gin and MCP interfaces

Add comprehensive Feed detail page support:
- Create new FeedDetailAction in xiaohongshu/feed_detail.go
- Add HTTP API endpoint POST /api/v1/feeds/detail
- Add MCP tool 'get_feed_detail' for MCP protocol support
- Support feed_id and xsec_token parameters (both required)
- Raw __INITIAL_STATE__ JSON data saved to feed_detail.json
- Return structured data for both HTTP and MCP interfaces

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

Co-Authored-By: Claude <noreply@anthropic.com>

* feat: enhance feed detail functionality with MCP interface improvements

- Add comprehensive feed detail page support with proper data extraction
- Create dedicated feed_detail.go file for FeedDetailAction
- Optimize Go struct definitions based on actual JSON data analysis
- Remove unnecessary fields from FeedDetail, DetailImageInfo, CommentList, and Comment structs
- Update MCP interface description to reflect comment retrieval capability
- Support both HTTP REST API and MCP protocol interfaces
- Implement proper Vue 3 reactive data extraction from window.__INITIAL_STATE__
- Include feed content, user info, interaction data, and comment lists

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

Co-Authored-By: Claude <noreply@anthropic.com>

* fix: restore JSON file writing for testing and improve code structure

- Restore feed_detail.json file writing for testing purposes
- Improve error handling by separating marshal and unmarshal steps
- Keep the original data extraction logic for complex Vue reactive data structure

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

Co-Authored-By: Claude <noreply@anthropic.com>

* refactor: simplify JSON unmarshaling using struct instead of map[string]any

- Replace complex map[string]any extraction with direct struct unmarshaling
- Define inline struct matching the actual JSON response structure
- Remove unnecessary extractFeedDetailData and extractNestedValue methods
- Significantly reduce code complexity and improve readability

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

Co-Authored-By: Claude <noreply@anthropic.com>

* docs: improve MCP interface descriptions for better usability

- Enhance get_feed_detail parameter descriptions with clear source information
- Clarify publish_content images parameter supports both local paths and URLs
- Improve search_feeds description to specify supported search types
- Keep descriptions concise and practical without over-complication

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

Co-Authored-By: Claude <noreply@anthropic.com>

* fix: revert search_feeds keyword description to keep it simple

- Remove unnecessary details from keyword description
- Keep interface descriptions concise and clear

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

Co-Authored-By: Claude <noreply@anthropic.com>

---------

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

service.go

@@ -167,3 +167,28 @@ func (s *XiaohongshuService) SearchFeeds(ctx context.Context, keyword string) (*
 
 	return response, nil
 }
+
+// GetFeedDetail 获取Feed详情
+func (s *XiaohongshuService) GetFeedDetail(ctx context.Context, feedID, xsecToken string) (*FeedDetailResponse, error) {
+	b := browser.NewBrowser(configs.IsHeadless())
+	defer b.Close()
+
+	page := b.NewPage()
+	defer page.Close()
+
+	// 创建 Feed 详情 action
+	action := xiaohongshu.NewFeedDetailAction(page)
+
+	// 获取 Feed 详情
+	result, err := action.GetFeedDetail(ctx, feedID, xsecToken)
+	if err != nil {
+		return nil, err
+	}
+
+	response := &FeedDetailResponse{
+		FeedID: feedID,
+		Data:   result,
+	}
+
+	return response, nil
+}