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>

mcp_handlers.go

@@ -162,4 +162,64 @@ func (s *AppServer) handleSearchFeeds(ctx context.Context, args map[string]inter
 			Text: string(jsonData),
 		}},
 	}
-}
+}
+
+// handleGetFeedDetail 处理获取Feed详情
+func (s *AppServer) handleGetFeedDetail(ctx context.Context, args map[string]any) *MCPToolResult {
+	logrus.Info("MCP: 获取Feed详情")
+
+	// 解析参数
+	feedID, ok := args["feed_id"].(string)
+	if !ok || feedID == "" {
+		return &MCPToolResult{
+			Content: []MCPContent{{
+				Type: "text",
+				Text: "获取Feed详情失败: 缺少feed_id参数",
+			}},
+			IsError: true,
+		}
+	}
+
+	xsecToken, ok := args["xsec_token"].(string)
+	if !ok || xsecToken == "" {
+		return &MCPToolResult{
+			Content: []MCPContent{{
+				Type: "text",
+				Text: "获取Feed详情失败: 缺少xsec_token参数",
+			}},
+			IsError: true,
+		}
+	}
+
+	logrus.Infof("MCP: 获取Feed详情 - Feed ID: %s", feedID)
+
+	result, err := s.xiaohongshuService.GetFeedDetail(ctx, feedID, xsecToken)
+	if err != nil {
+		return &MCPToolResult{
+			Content: []MCPContent{{
+				Type: "text",
+				Text: "获取Feed详情失败: " + err.Error(),
+			}},
+			IsError: true,
+		}
+	}
+
+	// 格式化输出，转换为JSON字符串
+	jsonData, err := json.MarshalIndent(result, "", "  ")
+	if err != nil {
+		return &MCPToolResult{
+			Content: []MCPContent{{
+				Type: "text",
+				Text: fmt.Sprintf("获取Feed详情成功，但序列化失败: %v", err),
+			}},
+			IsError: true,
+		}
+	}
+
+	return &MCPToolResult{
+		Content: []MCPContent{{
+			Type: "text",
+			Text: string(jsonData),
+		}},
+	}
+}