feat: add Grok, OpenAI, Claude, Gemini, Kimi AI providers

- Add new MCP clients for Grok (xAI), OpenAI, Claude, Gemini, Kimi
- Update auto_trader, backtest, and strategy to support all providers
- Add provider icons and fix SVG gradient conflicts
- Add API application links and hints in model config modal
- Show model version in AI model list cards
- Add Chinese/English translations for provider hints
- Remove deprecated traders component files

mcp/gemini_client.go

@@ -0,0 +1,71 @@
+package mcp
+
+import (
+	"net/http"
+)
+
+const (
+	ProviderGemini       = "gemini"
+	DefaultGeminiBaseURL = "https://generativelanguage.googleapis.com/v1beta/openai"
+	DefaultGeminiModel   = "gemini-3-pro-preview"
+)
+
+type GeminiClient struct {
+	*Client
+}
+
+// NewGeminiClient creates Gemini client (backward compatible)
+func NewGeminiClient() AIClient {
+	return NewGeminiClientWithOptions()
+}
+
+// NewGeminiClientWithOptions creates Gemini client (supports options pattern)
+func NewGeminiClientWithOptions(opts ...ClientOption) AIClient {
+	// 1. Create Gemini preset options
+	geminiOpts := []ClientOption{
+		WithProvider(ProviderGemini),
+		WithModel(DefaultGeminiModel),
+		WithBaseURL(DefaultGeminiBaseURL),
+	}
+
+	// 2. Merge user options (user options have higher priority)
+	allOpts := append(geminiOpts, opts...)
+
+	// 3. Create base client
+	baseClient := NewClient(allOpts...).(*Client)
+
+	// 4. Create Gemini client
+	geminiClient := &GeminiClient{
+		Client: baseClient,
+	}
+
+	// 5. Set hooks to point to GeminiClient (implement dynamic dispatch)
+	baseClient.hooks = geminiClient
+
+	return geminiClient
+}
+
+func (c *GeminiClient) SetAPIKey(apiKey string, customURL string, customModel string) {
+	c.APIKey = apiKey
+
+	if len(apiKey) > 8 {
+		c.logger.Infof("🔧 [MCP] Gemini API Key: %s...%s", apiKey[:4], apiKey[len(apiKey)-4:])
+	}
+	if customURL != "" {
+		c.BaseURL = customURL
+		c.logger.Infof("🔧 [MCP] Gemini using custom BaseURL: %s", customURL)
+	} else {
+		c.logger.Infof("🔧 [MCP] Gemini using default BaseURL: %s", c.BaseURL)
+	}
+	if customModel != "" {
+		c.Model = customModel
+		c.logger.Infof("🔧 [MCP] Gemini using custom Model: %s", customModel)
+	} else {
+		c.logger.Infof("🔧 [MCP] Gemini using default Model: %s", c.Model)
+	}
+}
+
+// Gemini OpenAI-compatible API uses standard Bearer auth
+func (c *GeminiClient) setAuthHeader(reqHeaders http.Header) {
+	c.Client.setAuthHeader(reqHeaders)
+}