feat: add batch command execution from files

Implemented roadmap #3: Batch operations from file.

Features:
- batch <file> or source <file> - Execute commands from script file
- Skips empty lines and comments (lines starting with #)
- Shows line numbers during execution for easy debugging
- Blocks exit/quit commands in batch mode (won't exit shell)
- Displays execution summary with counts

Implementation:
- Refactored main loop to extract executeCommand() method
- Created cmd_batch.go with batch file processor
- Reads file line by line, processes each command
- Summary shows total lines, executed count, and skipped count

Example batch file:
  # Connect and setup
  connect http://localhost:8080
  auth <token>

  # Batch insert
  put key1 '{"data":"value1"}'
  put key2 '{"data":"value2"}'

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

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

main.go

@@ -8,6 +8,67 @@ import (
 	"github.com/chzyer/readline"
 )
 
+// executeCommand executes a single command line
+func (c *KVSClient) executeCommand(line string) bool {
+	parts := parseCommand(line)
+	if len(parts) == 0 {
+		return true
+	}
+
+	cmd := parts[0]
+	args := parts[1:]
+
+	switch cmd {
+	case "exit", "quit":
+		fmt.Println("Goodbye!")
+		return false
+	case "clear":
+		print("\033[H\033[2J")
+	case "help":
+		c.handleHelp(args)
+	case "connect":
+		c.handleConnect(args)
+	case "auth":
+		c.handleAuth(args)
+	case "profile":
+		c.handleProfile(args)
+	case "get":
+		c.handleGet(args)
+	case "put":
+		c.handlePut(args)
+	case "delete":
+		c.handleDelete(args)
+	case "meta":
+		c.handleMeta(args)
+	case "members":
+		c.handleMembers(args)
+	case "health":
+		c.handleHealth(args)
+	case "user":
+		if len(args) > 0 {
+			switch args[0] {
+			case "get":
+				c.handleUserGet(args[1:])
+			case "create":
+				c.handleUserCreate(args[1:])
+			default:
+				fmt.Println(red("Unknown user command:"), args[0])
+				fmt.Println("Type 'help' for available commands")
+			}
+		} else {
+			c.handleUserList(args)
+		}
+	case "group":
+		c.handleGroup(args)
+	case "batch", "source":
+		c.handleBatch(args, c.executeCommand)
+	default:
+		fmt.Println(red("Unknown command:"), cmd)
+		fmt.Println("Type 'help' for available commands")
+	}
+	return true
+}
+
 func main() {
 	client := NewKVSClient("http://localhost:8090")
 
@@ -47,59 +108,8 @@ func main() {
 			continue
 		}
 
-		parts := parseCommand(line)
-		if len(parts) == 0 {
-			continue
-		}
-
-		cmd := parts[0]
-		args := parts[1:]
-
-		switch cmd {
-		case "exit", "quit":
-			fmt.Println("Goodbye!")
+		if !client.executeCommand(line) {
 			return
-		case "clear":
-			print("\033[H\033[2J")
-		case "help":
-			client.handleHelp(args)
-		case "connect":
-			client.handleConnect(args)
-		case "auth":
-			client.handleAuth(args)
-		case "profile":
-			client.handleProfile(args)
-		case "get":
-			client.handleGet(args)
-		case "put":
-			client.handlePut(args)
-		case "delete":
-			client.handleDelete(args)
-		case "meta":
-			client.handleMeta(args)
-		case "members":
-			client.handleMembers(args)
-		case "health":
-			client.handleHealth(args)
-		case "user":
-			if len(args) > 0 {
-				switch args[0] {
-				case "get":
-					client.handleUserGet(args[1:])
-				case "create":
-					client.handleUserCreate(args[1:])
-				default:
-					fmt.Println(red("Unknown user command:"), args[0])
-					fmt.Println("Type 'help' for available commands")
-				}
-			} else {
-				client.handleUserList(args)
-			}
-		case "group":
-			client.handleGroup(args)
-		default:
-			fmt.Println(red("Unknown command:"), cmd)
-			fmt.Println("Type 'help' for available commands")
 		}
 	}
 }