Implement complete content injection and enhancement pipeline

- Add content API client with HTTP and mock implementations
- Implement HTML content injection with database content replacement
- Create enhance command for build-time content injection
- Integrate enhancement with servedev for live development workflow
- Add editor asset injection and serving (/_insertr/ endpoints)
- Support on-the-fly HTML enhancement during development
- Enable complete 'Tailwind of CMS' workflow: parse → inject → serve

insertr-cli/cmd/enhance.go

@@ -0,0 +1,76 @@
+package cmd
+
+import (
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"github.com/insertr/cli/pkg/content"
+)
+
+var enhanceCmd = &cobra.Command{
+	Use:   "enhance [input-dir]",
+	Short: "Enhance HTML files by injecting content from database",
+	Long: `Enhance processes HTML files and injects latest content from the database
+while adding editing capabilities. This is the core build-time enhancement
+process that transforms static HTML into an editable CMS.`,
+	Args: cobra.ExactArgs(1),
+	Run:  runEnhance,
+}
+
+var (
+	outputDir   string
+	apiURL      string
+	apiKey      string
+	siteID      string
+	mockContent bool
+)
+
+func init() {
+	rootCmd.AddCommand(enhanceCmd)
+
+	enhanceCmd.Flags().StringVarP(&outputDir, "output", "o", "./dist", "Output directory for enhanced files")
+	enhanceCmd.Flags().StringVar(&apiURL, "api-url", "", "Content API URL")
+	enhanceCmd.Flags().StringVar(&apiKey, "api-key", "", "API key for authentication")
+	enhanceCmd.Flags().StringVarP(&siteID, "site-id", "s", "demo", "Site ID for content lookup")
+	enhanceCmd.Flags().BoolVar(&mockContent, "mock", true, "Use mock content for development")
+}
+
+func runEnhance(cmd *cobra.Command, args []string) {
+	inputDir := args[0]
+
+	// Validate input directory
+	if _, err := os.Stat(inputDir); os.IsNotExist(err) {
+		log.Fatalf("Input directory does not exist: %s", inputDir)
+	}
+
+	// Create content client
+	var client content.ContentClient
+	if mockContent {
+		fmt.Printf("🧪 Using mock content for development\n")
+		client = content.NewMockClient()
+	} else {
+		if apiURL == "" {
+			log.Fatal("API URL required when not using mock content (use --api-url)")
+		}
+		fmt.Printf("🌐 Using content API: %s\n", apiURL)
+		client = content.NewHTTPClient(apiURL, apiKey)
+	}
+
+	// Create enhancer
+	enhancer := content.NewEnhancer(client, siteID)
+
+	fmt.Printf("🚀 Starting enhancement process...\n")
+	fmt.Printf("📁 Input: %s\n", inputDir)
+	fmt.Printf("📁 Output: %s\n", outputDir)
+	fmt.Printf("🏷️  Site ID: %s\n\n", siteID)
+
+	// Enhance directory
+	if err := enhancer.EnhanceDirectory(inputDir, outputDir); err != nil {
+		log.Fatalf("Enhancement failed: %v", err)
+	}
+
+	fmt.Printf("\n✅ Enhancement complete! Enhanced files available in: %s\n", outputDir)
+}