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

backtest/ai_client.go

@@ -5,15 +5,17 @@ import (
 	"strings"
 
 	"nofx/mcp"
+	_ "nofx/mcp/payment"
+	_ "nofx/mcp/provider"
 )
 
 // configureMCPClient creates/clones an MCP client based on configuration (returns mcp.AIClient interface).
 // Note: mcp.New() returns an interface type; here we convert to concrete implementation before copying to avoid concurrent shared state.
 func configureMCPClient(cfg BacktestConfig, base mcp.AIClient) (mcp.AIClient, error) {
-	provider := strings.ToLower(strings.TrimSpace(cfg.AICfg.Provider))
+	providerName := strings.ToLower(strings.TrimSpace(cfg.AICfg.Provider))
 
-	// DeepSeek
-	if provider == "" || provider == "inherit" || provider == "default" {
+	// Inherit base client
+	if providerName == "" || providerName == "inherit" || providerName == "default" {
 		client := cloneBaseClient(base)
 		if cfg.AICfg.APIKey != "" || cfg.AICfg.BaseURL != "" || cfg.AICfg.Model != "" {
 			client.SetAPIKey(cfg.AICfg.APIKey, cfg.AICfg.BaseURL, cfg.AICfg.Model)
@@ -21,143 +23,49 @@ func configureMCPClient(cfg BacktestConfig, base mcp.AIClient) (mcp.AIClient, er
 		return client, nil
 	}
 
-	switch provider {
-	case "deepseek":
-		if cfg.AICfg.APIKey == "" {
-			return nil, fmt.Errorf("deepseek provider requires api key")
-		}
-		ds := mcp.NewDeepSeekClientWithOptions()
-		ds.(*mcp.DeepSeekClient).SetAPIKey(cfg.AICfg.APIKey, cfg.AICfg.BaseURL, cfg.AICfg.Model)
-		return ds, nil
-	case "qwen":
-		if cfg.AICfg.APIKey == "" {
-			return nil, fmt.Errorf("qwen provider requires api key")
-		}
-		qc := mcp.NewQwenClientWithOptions()
-		qc.(*mcp.QwenClient).SetAPIKey(cfg.AICfg.APIKey, cfg.AICfg.BaseURL, cfg.AICfg.Model)
-		return qc, nil
-	case "claude":
-		if cfg.AICfg.APIKey == "" {
-			return nil, fmt.Errorf("claude provider requires api key")
-		}
-		cc := mcp.NewClaudeClientWithOptions()
-		cc.(*mcp.ClaudeClient).SetAPIKey(cfg.AICfg.APIKey, cfg.AICfg.BaseURL, cfg.AICfg.Model)
-		return cc, nil
-	case "kimi":
-		if cfg.AICfg.APIKey == "" {
-			return nil, fmt.Errorf("kimi provider requires api key")
-		}
-		kc := mcp.NewKimiClientWithOptions()
-		kc.(*mcp.KimiClient).SetAPIKey(cfg.AICfg.APIKey, cfg.AICfg.BaseURL, cfg.AICfg.Model)
-		return kc, nil
-	case "gemini":
-		if cfg.AICfg.APIKey == "" {
-			return nil, fmt.Errorf("gemini provider requires api key")
-		}
-		gc := mcp.NewGeminiClientWithOptions()
-		gc.(*mcp.GeminiClient).SetAPIKey(cfg.AICfg.APIKey, cfg.AICfg.BaseURL, cfg.AICfg.Model)
-		return gc, nil
-	case "grok":
-		if cfg.AICfg.APIKey == "" {
-			return nil, fmt.Errorf("grok provider requires api key")
-		}
-		grokC := mcp.NewGrokClientWithOptions()
-		grokC.(*mcp.GrokClient).SetAPIKey(cfg.AICfg.APIKey, cfg.AICfg.BaseURL, cfg.AICfg.Model)
-		return grokC, nil
-	case "openai":
-		if cfg.AICfg.APIKey == "" {
-			return nil, fmt.Errorf("openai provider requires api key")
-		}
-		oaiC := mcp.NewOpenAIClientWithOptions()
-		oaiC.(*mcp.OpenAIClient).SetAPIKey(cfg.AICfg.APIKey, cfg.AICfg.BaseURL, cfg.AICfg.Model)
-		return oaiC, nil
-	case "minimax":
-		if cfg.AICfg.APIKey == "" {
-			return nil, fmt.Errorf("minimax provider requires api key")
-		}
-		mmC := mcp.NewMiniMaxClientWithOptions()
-		mmC.(*mcp.MiniMaxClient).SetAPIKey(cfg.AICfg.APIKey, cfg.AICfg.BaseURL, cfg.AICfg.Model)
-		return mmC, nil
-	case "blockrun-base":
-		if cfg.AICfg.APIKey == "" {
-			return nil, fmt.Errorf("blockrun-base provider requires wallet private key")
-		}
-		brBase := mcp.NewBlockRunBaseClient()
-		brBase.SetAPIKey(cfg.AICfg.APIKey, "", cfg.AICfg.Model)
-		return brBase, nil
-	case "blockrun-sol":
-		if cfg.AICfg.APIKey == "" {
-			return nil, fmt.Errorf("blockrun-sol provider requires wallet keypair")
-		}
-		brSol := mcp.NewBlockRunSolClient()
-		brSol.SetAPIKey(cfg.AICfg.APIKey, "", cfg.AICfg.Model)
-		return brSol, nil
-	case "claw402":
-		if cfg.AICfg.APIKey == "" {
-			return nil, fmt.Errorf("claw402 provider requires wallet private key")
-		}
-		claw := mcp.NewClaw402Client()
-		claw.SetAPIKey(cfg.AICfg.APIKey, "", cfg.AICfg.Model)
-		return claw, nil
-	case "custom":
+	// Custom provider uses cloned base
+	if providerName == "custom" {
 		if cfg.AICfg.BaseURL == "" || cfg.AICfg.APIKey == "" || cfg.AICfg.Model == "" {
 			return nil, fmt.Errorf("custom provider requires base_url, api key and model")
 		}
 		client := cloneBaseClient(base)
 		client.SetAPIKey(cfg.AICfg.APIKey, cfg.AICfg.BaseURL, cfg.AICfg.Model)
 		return client, nil
-	default:
+	}
+
+	// Create client via registry
+	client := mcp.NewAIClientByProvider(providerName)
+	if client == nil {
 		return nil, fmt.Errorf("unsupported ai provider %s", cfg.AICfg.Provider)
 	}
+
+	if cfg.AICfg.APIKey == "" {
+		return nil, fmt.Errorf("%s provider requires api key", providerName)
+	}
+
+	// Payment providers ignore custom URL
+	switch providerName {
+	case "blockrun-base", "blockrun-sol", "claw402":
+		client.SetAPIKey(cfg.AICfg.APIKey, "", cfg.AICfg.Model)
+	default:
+		client.SetAPIKey(cfg.AICfg.APIKey, cfg.AICfg.BaseURL, cfg.AICfg.Model)
+	}
+	return client, nil
 }
 
 // cloneBaseClient copies the base client to avoid shared mutable state.
+// Uses the ClientEmbedder interface to extract the underlying *mcp.Client
+// from any provider type that embeds it.
 func cloneBaseClient(base mcp.AIClient) *mcp.Client {
-	// Prefer to reuse the passed-in base client (deep copy)
-	switch c := base.(type) {
-	case *mcp.Client:
+	if embedder, ok := base.(mcp.ClientEmbedder); ok {
+		if inner := embedder.BaseClient(); inner != nil {
+			cp := *inner
+			return &cp
+		}
+	}
+	if c, ok := base.(*mcp.Client); ok {
 		cp := *c
 		return &cp
-	case *mcp.DeepSeekClient:
-		if c != nil && c.Client != nil {
-			cp := *c.Client
-			return &cp
-		}
-	case *mcp.QwenClient:
-		if c != nil && c.Client != nil {
-			cp := *c.Client
-			return &cp
-		}
-	case *mcp.ClaudeClient:
-		if c != nil && c.Client != nil {
-			cp := *c.Client
-			return &cp
-		}
-	case *mcp.KimiClient:
-		if c != nil && c.Client != nil {
-			cp := *c.Client
-			return &cp
-		}
-	case *mcp.GeminiClient:
-		if c != nil && c.Client != nil {
-			cp := *c.Client
-			return &cp
-		}
-	case *mcp.GrokClient:
-		if c != nil && c.Client != nil {
-			cp := *c.Client
-			return &cp
-		}
-	case *mcp.OpenAIClient:
-		if c != nil && c.Client != nil {
-			cp := *c.Client
-			return &cp
-		}
-	case *mcp.MiniMaxClient:
-		if c != nil && c.Client != nil {
-			cp := *c.Client
-			return &cp
-		}
 	}
 	// Fall back to a new default client
 	return mcp.NewClient().(*mcp.Client)