feat(sdk): ✨ Implement EdgeXR Master Controller Go SDK foundation

Phase 1 Implementation - Core SDK foundation with typed APIs:

## New Components Added:
- **SDK Package Structure**: `/sdk/client`, `/sdk/internal/http`, `/sdk/examples`
- **Core Types**: App, AppInstance, Cloudlet with JSON marshaling
- **HTTP Transport**: Resilient HTTP client with go-retryablehttp
- **Auth System**: Pluggable providers (StaticToken, NoAuth)
- **Client**: Configurable SDK client with retry and logging options

## API Implementation:
- **App Management**: CreateApp, ShowApp, ShowApps, DeleteApp
- **Error Handling**: Structured APIError with status codes and messages
- **Response Parsing**: EdgeXR streaming JSON response support
- **Context Support**: All APIs accept context.Context for timeouts/cancellation

## Testing & Examples:
- **Unit Tests**: Comprehensive test suite with httptest mock servers
- **Example App**: Complete app lifecycle demonstration in examples/deploy_app.go
- **Test Coverage**: Create, show, list, delete operations with error conditions

## Build Infrastructure:
- **Makefile**: Automated code generation, testing, and building
- **Dependencies**: Added go-retryablehttp, testify, oapi-codegen
- **Configuration**: oapi-codegen.yaml for type generation

## API Mapping:
- CreateApp → POST /auth/ctrl/CreateApp
- ShowApp → POST /auth/ctrl/ShowApp
- DeleteApp → POST /auth/ctrl/DeleteApp

Following existing prototype patterns while adding type safety, retry logic,
and comprehensive error handling. Ready for Phase 2 AppInstance APIs.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

sdk/examples/deploy_app.go

@@ -0,0 +1,119 @@
+// ABOUTME: Example demonstrating EdgeXR SDK usage for app deployment workflow
+// ABOUTME: Shows app creation, querying, and cleanup using the typed SDK APIs
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"time"
+
+	"edp.buildth.ing/DevFW-CICD/edge-connect-client/sdk/client"
+)
+
+func main() {
+	// Configure SDK client
+	baseURL := getEnvOrDefault("EDGEXR_BASE_URL", "https://hub.apps.edge.platform.mg3.mdb.osc.live/api/v1")
+	token := getEnvOrDefault("EDGEXR_TOKEN", "")
+
+	if token == "" {
+		log.Fatal("EDGEXR_TOKEN environment variable is required")
+	}
+
+	// Create SDK client with authentication and logging
+	client := client.NewClient(baseURL,
+		client.WithHTTPClient(&http.Client{Timeout: 30 * time.Second}),
+		client.WithAuthProvider(client.NewStaticTokenProvider(token)),
+		client.WithLogger(log.Default()),
+	)
+
+	ctx := context.Background()
+
+	// Example application to deploy
+	app := &client.NewAppInput{
+		Region: "us-west",
+		App: client.App{
+			Key: client.AppKey{
+				Organization: "myorg",
+				Name:         "my-edge-app",
+				Version:      "1.0.0",
+			},
+			Deployment:    "kubernetes",
+			ImageType:     "ImageTypeDocker",
+			ImagePath:     "nginx:latest",
+			DefaultFlavor: client.Flavor{Name: "m4.small"},
+		},
+	}
+
+	// Demonstrate app lifecycle
+	if err := demonstrateAppLifecycle(ctx, client, app); err != nil {
+		log.Fatalf("App lifecycle demonstration failed: %v", err)
+	}
+
+	fmt.Println("✅ SDK example completed successfully!")
+}
+
+func demonstrateAppLifecycle(ctx context.Context, c *client.Client, input *client.NewAppInput) error {
+	appKey := input.App.Key
+	region := input.Region
+
+	fmt.Printf("🚀 Demonstrating EdgeXR SDK with app: %s/%s v%s\n",
+		appKey.Organization, appKey.Name, appKey.Version)
+
+	// Step 1: Create the application
+	fmt.Println("\n1. Creating application...")
+	if err := c.CreateApp(ctx, input); err != nil {
+		return fmt.Errorf("failed to create app: %w", err)
+	}
+	fmt.Printf("✅ App created: %s/%s v%s\n", appKey.Organization, appKey.Name, appKey.Version)
+
+	// Step 2: Query the application
+	fmt.Println("\n2. Querying application...")
+	app, err := c.ShowApp(ctx, appKey, region)
+	if err != nil {
+		return fmt.Errorf("failed to show app: %w", err)
+	}
+	fmt.Printf("✅ App found: %s/%s v%s (deployment: %s)\n",
+		app.Key.Organization, app.Key.Name, app.Key.Version, app.Deployment)
+
+	// Step 3: List applications in the organization
+	fmt.Println("\n3. Listing applications...")
+	filter := client.AppKey{Organization: appKey.Organization}
+	apps, err := c.ShowApps(ctx, filter, region)
+	if err != nil {
+		return fmt.Errorf("failed to list apps: %w", err)
+	}
+	fmt.Printf("✅ Found %d applications in organization '%s'\n", len(apps), appKey.Organization)
+
+	// Step 4: Clean up - delete the application
+	fmt.Println("\n4. Cleaning up...")
+	if err := c.DeleteApp(ctx, appKey, region); err != nil {
+		return fmt.Errorf("failed to delete app: %w", err)
+	}
+	fmt.Printf("✅ App deleted: %s/%s v%s\n", appKey.Organization, appKey.Name, appKey.Version)
+
+	// Step 5: Verify deletion
+	fmt.Println("\n5. Verifying deletion...")
+	_, err = c.ShowApp(ctx, appKey, region)
+	if err != nil {
+		if fmt.Sprintf("%v", err) == client.ErrResourceNotFound.Error() {
+			fmt.Printf("✅ App successfully deleted (not found)\n")
+		} else {
+			return fmt.Errorf("unexpected error verifying deletion: %w", err)
+		}
+	} else {
+		return fmt.Errorf("app still exists after deletion")
+	}
+
+	return nil
+}
+
+func getEnvOrDefault(key, defaultValue string) string {
+	if value := os.Getenv(key); value != "" {
+		return value
+	}
+	return defaultValue
+}