Improve(interface): replace some struct with interface for testing (#994)

* fix(trader): get peakPnlPct using posKey
* fix(docs): keep readme at the same page
* improve(interface): replace with interface
* refactor mcp
---------
Co-authored-by: zbhan <zbhan@freewheel.tv>

mcp/qwen_client.go

@@ -0,0 +1,53 @@
+package mcp
+
+import (
+	"log"
+	"net/http"
+)
+
+const (
+	ProviderQwen       = "qwen"
+	DefaultQwenBaseURL = "https://dashscope.aliyuncs.com/compatible-mode/v1"
+	DefaultQwenModel   = "qwen3-max"
+)
+
+type QwenClient struct {
+	*Client
+}
+
+func NewQwenClient() AIClient {
+	client := New().(*Client)
+	client.Provider = ProviderQwen
+	client.Model = DefaultQwenModel
+	client.BaseURL = DefaultQwenBaseURL
+	return &QwenClient{
+		Client: client,
+	}
+}
+
+func (qwenClient *QwenClient) SetAPIKey(apiKey string, customURL string, customModel string) {
+	if qwenClient.Client == nil {
+		qwenClient.Client = New().(*Client)
+	}
+	qwenClient.Client.APIKey = apiKey
+
+	if len(apiKey) > 8 {
+		log.Printf("🔧 [MCP] Qwen API Key: %s...%s", apiKey[:4], apiKey[len(apiKey)-4:])
+	}
+	if customURL != "" {
+		qwenClient.Client.BaseURL = customURL
+		log.Printf("🔧 [MCP] Qwen 使用自定义 BaseURL: %s", customURL)
+	} else {
+		log.Printf("🔧 [MCP] Qwen 使用默认 BaseURL: %s", qwenClient.Client.BaseURL)
+	}
+	if customModel != "" {
+		qwenClient.Client.Model = customModel
+		log.Printf("🔧 [MCP] Qwen 使用自定义 Model: %s", customModel)
+	} else {
+		log.Printf("🔧 [MCP] Qwen 使用默认 Model: %s", qwenClient.Client.Model)
+	}
+}
+
+func (qwenClient *QwenClient) setAuthHeader(reqHeaders http.Header) {
+	qwenClient.Client.setAuthHeader(reqHeaders)
+}