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/deepseek_client.go

@@ -0,0 +1,53 @@
+package mcp
+
+import (
+	"log"
+	"net/http"
+)
+
+const (
+	ProviderDeepSeek       = "deepseek"
+	DefaultDeepSeekBaseURL = "https://api.deepseek.com/v1"
+	DefaultDeepSeekModel   = "deepseek-chat"
+)
+
+type DeepSeekClient struct {
+	*Client
+}
+
+func NewDeepSeekClient() AIClient {
+	client := New().(*Client)
+	client.Provider = ProviderDeepSeek
+	client.Model = DefaultDeepSeekModel
+	client.BaseURL = DefaultDeepSeekBaseURL
+	return &DeepSeekClient{
+		Client: client,
+	}
+}
+
+func (dsClient *DeepSeekClient) SetAPIKey(apiKey string, customURL string, customModel string) {
+	if dsClient.Client == nil {
+		dsClient.Client = New().(*Client)
+	}
+	dsClient.Client.APIKey = apiKey
+
+	if len(apiKey) > 8 {
+		log.Printf("🔧 [MCP] DeepSeek API Key: %s...%s", apiKey[:4], apiKey[len(apiKey)-4:])
+	}
+	if customURL != "" {
+		dsClient.Client.BaseURL = customURL
+		log.Printf("🔧 [MCP] DeepSeek 使用自定义 BaseURL: %s", customURL)
+	} else {
+		log.Printf("🔧 [MCP] DeepSeek 使用默认 BaseURL: %s", dsClient.Client.BaseURL)
+	}
+	if customModel != "" {
+		dsClient.Client.Model = customModel
+		log.Printf("🔧 [MCP] DeepSeek 使用自定义 Model: %s", customModel)
+	} else {
+		log.Printf("🔧 [MCP] DeepSeek 使用默认 Model: %s", dsClient.Client.Model)
+	}
+}
+
+func (dsClient *DeepSeekClient) setAuthHeader(reqHeaders http.Header) {
+	dsClient.Client.setAuthHeader(reqHeaders)
+}