aider: Renamed CustomLogger to CustomHandler.

# Aider chat conversation:

USER: rename CustomLogger to CustomHandler

ASSISTANT: To make this change we need to modify `simplelog.go`:

1. Replace all instances of `CustomLogger` with `CustomHandler`.

Here are the *SEARCH/REPLACE* blocks:

simplelog.go
```go
<<<<<<< SEARCH
type CustomLogger struct {
	handlers []slog.Handler
}

func (cl *CustomLogger) Log(level slog.Level, message string, data ...slog.Field) error {
	for _, handler := range cl.handlers {
		if err := handler.Log(level, message, data...); err != nil {
			return err
		}
	}
	return nil
}

var ourCustomLogger *slog.Logger

func init() {
	ourCustomLogger = NewCustomLogger()
	slog.SetDefault(ourCustomLogger)
}

func NewCustomLogger() *CustomLogger {
	cl := &CustomLogger{}
=======
type CustomHandler struct {
	handlers []slog.Handler
}

func (cl *CustomHandler) Log(level slog.Level, message string, data ...slog.Field) error {
	for _, handler := range cl.handlers {
		if err := handler.Log(level, message, data...); err != nil {
			return err
		}
	}
	return nil
}

var ourCustomLogger *slog.Logger

func init() {
	ourCustomLogger = NewCustomHandler()
	slog.SetDefault(ourCustomLogger)
}

func NewCustomHandler() *CustomHandler {
	cl := &CustomHandler{}
>>>>>>> REPLACE
```

simplelog.go

@@ -13,11 +13,11 @@ var (
 	webhookURL    = os.Getenv("LOGGER_WEBHOOK_URL")
 )
 
-type CustomLogger struct {
+type CustomHandler struct {
 	handlers []slog.Handler
 }
 
-func (cl *CustomLogger) Log(level slog.Level, message string, data ...slog.Field) error {
+func (cl *CustomHandler) Log(level slog.Level, message string, data ...slog.Field) error {
 	for _, handler := range cl.handlers {
 		if err := handler.Log(level, message, data...); err != nil {
 			return err
@@ -29,12 +29,12 @@ func (cl *CustomLogger) Log(level slog.Level, message string, data ...slog.Field
 var ourCustomLogger *slog.Logger
 
 func init() {
-	ourCustomLogger = NewCustomLogger()
+	ourCustomLogger = NewCustomHandler()
 	slog.SetDefault(ourCustomLogger)
 }
 
-func NewCustomLogger() *CustomLogger {
+func NewCustomHandler() *CustomHandler {
-	cl := &CustomLogger{}
+	cl := &CustomHandler{}
 	if isatty.IsTerminal(os.Stdout.Fd()) {
 		cl.handlers = append(cl.handlers, NewConsoleHandler())
 	} else {