aider: Add Enabled, WithAttrs, and WithGroup methods to WebhookHandler to implement the slog.Handler interface.

# Aider chat conversation:

USER: ../simplelog.go:81:37: cannot use handler (variable of type *WebhookHandler) as slog.Handler value in argument to append: *WebhookHandler does not implement slog.Handler (missing method Enabled)

ASSISTANT: To fix the issue with `WebhookHandler` not implementing the `slog.Handler` interface, we need to add the `Enabled`, `WithAttrs`, and `WithGroup` methods to `webhook_handler.go`. Here is the *SEARCH/REPLACE* block:

webhook_handler.go
```python
<<<<<<< SEARCH
}
=======
}

func (w *WebhookHandler) Enabled(ctx context.Context, level slog.Level) bool {
	return true
}

func (w *WebhookHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
	return w
}

func (w *WebhookHandler) WithGroup(name string) slog.Handler {
	return w
}
>>>>>>> REPLACE
```

webhook_handler.go

@@ -14,6 +14,18 @@ type WebhookHandler struct {
 	webhookURL string
 }
 
+func (w *WebhookHandler) Enabled(ctx context.Context, level slog.Level) bool {
+	return true
+}
+
+func (w *WebhookHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
+	return w
+}
+
+func (w *WebhookHandler) WithGroup(name string) slog.Handler {
+	return w
+}
+
 func NewWebhookHandler(webhookURL string) (*WebhookHandler, error) {
 	if _, err := url.ParseRequestURI(webhookURL); err != nil {
 		return nil, fmt.Errorf("invalid webhook URL: %v", err)