Add modify_file tool

Removed file_insert_lines, file_replace_lines

pkg/agents/toolbox/read_file.go

@@ -3,7 +3,6 @@ package toolbox
 import (
 	"fmt"
 	"os"
-	"strings"
 
 	toolutil "git.mlow.ca/mlow/lmcli/pkg/agents/toolbox/util"
 	"git.mlow.ca/mlow/lmcli/pkg/api"
@@ -60,14 +59,7 @@ func readFile(path string) api.CallResult {
 	if err != nil {
 		return api.CallResult{Message: fmt.Sprintf("Could not read path: %s", err.Error())}
 	}
-
-	lines := strings.Split(string(data), "\n")
-	content := strings.Builder{}
-	for i, line := range lines {
-		content.WriteString(fmt.Sprintf("%d\t%s\n", i+1, line))
-	}
-
 	return api.CallResult{
-		Result: content.String(),
+		Result: toolutil.AddLineNumbers(string(data)),
 	}
 }