feat: add environment config import support in init

Closes #1

- Detect ANTHROPIC_BASE_URL and ANTHROPIC_AUTH_TOKEN from environment
- Offer to import existing configuration during init
- Test imported configuration before saving
- Add min helper function for safe string truncation
- Show masked auth token in detection output

This allows users who already have Claude Code configured via
environment variables to easily import their configuration into
the codes CLI management system.

Author: ourines

internal/commands/commands.go

@@ -15,6 +15,14 @@ import (
 	"codes/internal/ui"
 )
 
+// min returns the minimum of two integers
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
 func RunVersion() {
 	fmt.Printf("codes version dev (built unknown)\n")
 }
@@ -411,9 +419,90 @@ func RunInit() {
 	}
 	fmt.Println()
 
-	// 2. Check if config file exists
+	// 2. Check for existing environment variables
+	ui.ShowInfo("Checking for existing Claude configuration...")
+	baseURL := os.Getenv("ANTHROPIC_BASE_URL")
+	authToken := os.Getenv("ANTHROPIC_AUTH_TOKEN")
+
+	hasEnvConfig := false
+	if baseURL != "" && authToken != "" {
+		ui.ShowSuccess("✓ Found existing configuration in environment variables")
+		ui.ShowInfo("  ANTHROPIC_BASE_URL: %s", baseURL)
+		ui.ShowInfo("  ANTHROPIC_AUTH_TOKEN: %s...", authToken[:min(10, len(authToken))])
+		hasEnvConfig = true
+	} else if baseURL != "" || authToken != "" {
+		ui.ShowWarning("⚠ Incomplete environment configuration detected")
+		if baseURL != "" {
+			ui.ShowInfo("  ANTHROPIC_BASE_URL: %s", baseURL)
+		}
+		if authToken != "" {
+			ui.ShowInfo("  ANTHROPIC_AUTH_TOKEN: configured")
+		}
+	}
+	fmt.Println()
+
+	// 3. Check if config file exists
 	ui.ShowInfo("Checking configuration file...")
-	if _, err := os.Stat(config.ConfigPath); err != nil {
+	configExists := false
+	if _, err := os.Stat(config.ConfigPath); err == nil {
+		configExists = true
+	}
+
+	// If env config exists but no codes config, offer to import
+	if hasEnvConfig && !configExists {
+		fmt.Println()
+		ui.ShowInfo("Would you like to import this configuration? (y/n): ")
+		reader := bufio.NewReader(os.Stdin)
+		response, _ := reader.ReadString('\n')
+		response = strings.TrimSpace(strings.ToLower(response))
+
+		if response == "y" || response == "yes" {
+			// Prompt for configuration name
+			fmt.Print("Enter a name for this configuration (default: imported): ")
+			name, _ := reader.ReadString('\n')
+			name = strings.TrimSpace(name)
+			if name == "" {
+				name = "imported"
+			}
+
+			// Create and test configuration
+			ui.ShowLoading("Testing API connection...")
+			testConfig := config.APIConfig{
+				Name:               name,
+				AnthropicBaseURL:   baseURL,
+				AnthropicAuthToken: authToken,
+			}
+
+			var cfg config.Config
+			cfg.Configs = []config.APIConfig{testConfig}
+			cfg.Default = name
+
+			if config.TestAPIConfig(testConfig) {
+				ui.ShowSuccess("✓ API connection successful!")
+				testConfig.Status = "active"
+			} else {
+				ui.ShowWarning("⚠ API connection failed, but configuration will be saved")
+				testConfig.Status = "inactive"
+			}
+
+			cfg.Configs[0] = testConfig
+
+			// Save configuration
+			if err := config.SaveConfig(&cfg); err != nil {
+				ui.ShowError("Failed to save configuration", err)
+				allGood = false
+			} else {
+				ui.ShowSuccess("✓ Configuration imported successfully!")
+				ui.ShowInfo("  Name: %s", name)
+				ui.ShowInfo("  Status: %s", testConfig.Status)
+				configExists = true
+			}
+			fmt.Println()
+		}
+	}
+
+	// Continue with normal config check
+	if !configExists {
 		ui.ShowError("✗ Configuration file not found", nil)
 		ui.ShowInfo("  Expected location: %s", config.ConfigPath)
 		ui.ShowWarning("  Run 'codes add' to create your first configuration")
@@ -422,7 +511,7 @@ func RunInit() {
 		ui.ShowSuccess("✓ Configuration file exists")
 		ui.ShowInfo("  Location: %s", config.ConfigPath)
 
-		// 3. Validate configuration
+		// 4. Validate configuration
 		cfg, err := config.LoadConfig()
 		if err != nil {
 			ui.ShowError("✗ Failed to load configuration", err)