Init world. Basic registry API server

Work in progress .
This commit adds the core registry service implementation with methods to:
- Retrieve all registry entries
- List entries with cursor-based pagination
- Fetch specific server details by ID

internal/config/config.go

@@ -0,0 +1,56 @@
+package config
+
+import "os"
+
+// Config holds the application configuration
+type Config struct {
+	ServerAddress  string
+	DatabaseURL    string
+	DatabaseName   string
+	CollectionName string
+	LogLevel       string
+	Environment    string // Added environment field
+	Version        string // Application version
+}
+
+// NewConfig creates a new configuration with default values
+func NewConfig() *Config {
+	// Get environment from OS environment variable or default to "production"
+	env := os.Getenv("APP_ENV")
+	if env == "" {
+		env = "production"
+	}
+
+	// Get version from environment variable or default to "dev"
+	version := os.Getenv("APP_VERSION")
+	if version == "" {
+		version = "dev"
+	}
+
+	// Get database URL from environment variable or default to localhost
+	dbURL := os.Getenv("DATABASE_URL")
+	if dbURL == "" {
+		dbURL = "localhost:5432"
+	}
+
+	// Get database name from environment variable or default to "mcp_registry"
+	dbName := os.Getenv("DATABASE_NAME")
+	if dbName == "" {
+		dbName = "mcp-registry"
+	}
+	// Get collection name from environment variable or default to "entries"
+	collectionName := os.Getenv("COLLECTION_NAME")
+	if collectionName == "" {
+		collectionName = "servers_v2"
+	}
+
+	return &Config{
+		ServerAddress:  ":8080",
+		DatabaseURL:    dbURL,
+		DatabaseName:   dbName,
+		CollectionName: collectionName,
+		LogLevel:       "info",
+		Environment:    env,
+		Version:        version,
+	}
+}