refactor: restructure project directories for better modularity

- Delete llm/ dead code (3 files, zero references)
- Split mcp/ into sub-packages: mcp/provider/ (8 providers) and
  mcp/payment/ (4 payment clients) with registry pattern
- Export Client internal fields and ClientHooks interface for
  sub-package access
- Split api/server.go (3892 lines) into 8 domain-specific handler files
- Split trader/auto_trader.go (2296 lines) into 5 focused files
- Reorganize web/src/components/ flat files into auth/, charts/,
  trader/, common/, modals/, backtest/ subdirectories
- Update all consumer imports to use registry-based provider creation

mcp/provider/kimi.go

@@ -0,0 +1,73 @@
+package provider
+
+import (
+	"net/http"
+
+	"nofx/mcp"
+)
+
+const (
+	DefaultKimiBaseURL = "https://api.moonshot.ai/v1" // Global endpoint (use api.moonshot.cn for China)
+	DefaultKimiModel   = "moonshot-v1-auto"
+)
+
+func init() {
+	mcp.RegisterProvider(mcp.ProviderKimi, func(opts ...mcp.ClientOption) mcp.AIClient {
+		return NewKimiClientWithOptions(opts...)
+	})
+}
+
+type KimiClient struct {
+	*mcp.Client
+}
+
+func (c *KimiClient) BaseClient() *mcp.Client { return c.Client }
+
+// NewKimiClient creates Kimi (Moonshot) client (backward compatible)
+func NewKimiClient() mcp.AIClient {
+	return NewKimiClientWithOptions()
+}
+
+// NewKimiClientWithOptions creates Kimi client (supports options pattern)
+func NewKimiClientWithOptions(opts ...mcp.ClientOption) mcp.AIClient {
+	kimiOpts := []mcp.ClientOption{
+		mcp.WithProvider(mcp.ProviderKimi),
+		mcp.WithModel(DefaultKimiModel),
+		mcp.WithBaseURL(DefaultKimiBaseURL),
+	}
+
+	allOpts := append(kimiOpts, opts...)
+	baseClient := mcp.NewClient(allOpts...).(*mcp.Client)
+
+	kimiClient := &KimiClient{
+		Client: baseClient,
+	}
+
+	baseClient.Hooks = kimiClient
+	return kimiClient
+}
+
+func (c *KimiClient) SetAPIKey(apiKey string, customURL string, customModel string) {
+	c.APIKey = apiKey
+
+	if len(apiKey) > 8 {
+		c.Log.Infof("🔧 [MCP] Kimi API Key: %s...%s", apiKey[:4], apiKey[len(apiKey)-4:])
+	}
+	if customURL != "" {
+		c.BaseURL = customURL
+		c.Log.Infof("🔧 [MCP] Kimi using custom BaseURL: %s", customURL)
+	} else {
+		c.Log.Infof("🔧 [MCP] Kimi using default BaseURL: %s", c.BaseURL)
+	}
+	if customModel != "" {
+		c.Model = customModel
+		c.Log.Infof("🔧 [MCP] Kimi using custom Model: %s", customModel)
+	} else {
+		c.Log.Infof("🔧 [MCP] Kimi using default Model: %s", c.Model)
+	}
+}
+
+// Kimi uses standard OpenAI-compatible API
+func (c *KimiClient) SetAuthHeader(reqHeaders http.Header) {
+	c.Client.SetAuthHeader(reqHeaders)
+}