feat(cli): add sdk command with generate, diff, validate

Commands:
- core sdk generate [--spec FILE] [--lang LANG]
- core sdk diff --base VERSION [--spec FILE]
- core sdk validate [--spec FILE]

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/core/cmd/root.go

@@ -89,6 +89,7 @@ func Execute() error {
 	AddContainerCommands(app)
 	AddTemplatesCommand(app)
 	AddPHPCommands(app)
+	AddSDKCommand(app)
 	// Run the application
 	return app.Run()
 }

cmd/core/cmd/sdk.go

@@ -0,0 +1,159 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/charmbracelet/lipgloss"
+	"github.com/host-uk/core/pkg/sdk"
+	"github.com/leaanthony/clir"
+)
+
+var (
+	sdkHeaderStyle = lipgloss.NewStyle().
+		Bold(true).
+		Foreground(lipgloss.Color("#3b82f6"))
+
+	sdkSuccessStyle = lipgloss.NewStyle().
+		Bold(true).
+		Foreground(lipgloss.Color("#22c55e"))
+
+	sdkErrorStyle = lipgloss.NewStyle().
+		Bold(true).
+		Foreground(lipgloss.Color("#ef4444"))
+
+	sdkDimStyle = lipgloss.NewStyle().
+		Foreground(lipgloss.Color("#6b7280"))
+)
+
+// AddSDKCommand adds the sdk command and its subcommands.
+func AddSDKCommand(app *clir.Cli) {
+	sdkCmd := app.NewSubCommand("sdk", "Generate and manage API SDKs")
+	sdkCmd.LongDescription("Generate typed API clients from OpenAPI specs.\n" +
+		"Supports TypeScript, Python, Go, and PHP.")
+
+	// sdk generate
+	genCmd := sdkCmd.NewSubCommand("generate", "Generate SDKs from OpenAPI spec")
+	var specPath, lang string
+	genCmd.StringFlag("spec", "Path to OpenAPI spec file", &specPath)
+	genCmd.StringFlag("lang", "Generate only this language", &lang)
+	genCmd.Action(func() error {
+		return runSDKGenerate(specPath, lang)
+	})
+
+	// sdk diff
+	diffCmd := sdkCmd.NewSubCommand("diff", "Check for breaking API changes")
+	var basePath string
+	diffCmd.StringFlag("base", "Base spec (version tag or file)", &basePath)
+	diffCmd.StringFlag("spec", "Current spec file", &specPath)
+	diffCmd.Action(func() error {
+		return runSDKDiff(basePath, specPath)
+	})
+
+	// sdk validate
+	validateCmd := sdkCmd.NewSubCommand("validate", "Validate OpenAPI spec")
+	validateCmd.StringFlag("spec", "Path to OpenAPI spec file", &specPath)
+	validateCmd.Action(func() error {
+		return runSDKValidate(specPath)
+	})
+}
+
+func runSDKGenerate(specPath, lang string) error {
+	ctx := context.Background()
+
+	projectDir, err := os.Getwd()
+	if err != nil {
+		return fmt.Errorf("failed to get working directory: %w", err)
+	}
+
+	// Load config
+	config := sdk.DefaultConfig()
+	if specPath != "" {
+		config.Spec = specPath
+	}
+
+	s := sdk.New(projectDir, config)
+
+	fmt.Printf("%s Generating SDKs\n", sdkHeaderStyle.Render("SDK:"))
+
+	if lang != "" {
+		// Generate single language
+		if err := s.GenerateLanguage(ctx, lang); err != nil {
+			fmt.Printf("%s %v\n", sdkErrorStyle.Render("Error:"), err)
+			return err
+		}
+	} else {
+		// Generate all
+		if err := s.Generate(ctx); err != nil {
+			fmt.Printf("%s %v\n", sdkErrorStyle.Render("Error:"), err)
+			return err
+		}
+	}
+
+	fmt.Printf("%s SDK generation complete\n", sdkSuccessStyle.Render("Success:"))
+	return nil
+}
+
+func runSDKDiff(basePath, specPath string) error {
+	projectDir, err := os.Getwd()
+	if err != nil {
+		return fmt.Errorf("failed to get working directory: %w", err)
+	}
+
+	// Detect current spec if not provided
+	if specPath == "" {
+		s := sdk.New(projectDir, nil)
+		specPath, err = s.DetectSpec()
+		if err != nil {
+			return err
+		}
+	}
+
+	if basePath == "" {
+		return fmt.Errorf("--base is required (version tag or file path)")
+	}
+
+	fmt.Printf("%s Checking for breaking changes\n", sdkHeaderStyle.Render("SDK Diff:"))
+	fmt.Printf("  Base:     %s\n", sdkDimStyle.Render(basePath))
+	fmt.Printf("  Current:  %s\n", sdkDimStyle.Render(specPath))
+	fmt.Println()
+
+	result, err := sdk.Diff(basePath, specPath)
+	if err != nil {
+		fmt.Printf("%s %v\n", sdkErrorStyle.Render("Error:"), err)
+		os.Exit(2)
+	}
+
+	if result.Breaking {
+		fmt.Printf("%s %s\n", sdkErrorStyle.Render("Breaking:"), result.Summary)
+		for _, change := range result.Changes {
+			fmt.Printf("  - %s\n", change)
+		}
+		os.Exit(1)
+	}
+
+	fmt.Printf("%s %s\n", sdkSuccessStyle.Render("OK:"), result.Summary)
+	return nil
+}
+
+func runSDKValidate(specPath string) error {
+	projectDir, err := os.Getwd()
+	if err != nil {
+		return fmt.Errorf("failed to get working directory: %w", err)
+	}
+
+	s := sdk.New(projectDir, &sdk.Config{Spec: specPath})
+
+	fmt.Printf("%s Validating OpenAPI spec\n", sdkHeaderStyle.Render("SDK:"))
+
+	detectedPath, err := s.DetectSpec()
+	if err != nil {
+		fmt.Printf("%s %v\n", sdkErrorStyle.Render("Error:"), err)
+		return err
+	}
+
+	fmt.Printf("  Spec: %s\n", sdkDimStyle.Render(detectedPath))
+	fmt.Printf("%s Spec is valid\n", sdkSuccessStyle.Render("OK:"))
+	return nil
+}