feat(agent): support btw side questions (#2532)

pkg/commands/cmd_btw.go

@@ -0,0 +1,51 @@
+package commands
+
+import (
+	"context"
+	"strings"
+)
+
+func btwCommand() Definition {
+	return Definition{
+		Name:        "btw",
+		Description: "Ask a side question without changing session history",
+		Usage:       "/btw <question>",
+		Handler: func(ctx context.Context, req Request, rt *Runtime) error {
+			const emptyAnswerMsg = "The model returned an empty response. This may indicate a provider error or token limit."
+
+			if rt == nil || rt.AskSideQuestion == nil {
+				return req.Reply(unavailableMsg)
+			}
+
+			question := sideQuestionText(req.Text)
+			if question == "" {
+				return req.Reply("Usage: /btw <question>")
+			}
+
+			answer, err := rt.AskSideQuestion(ctx, question)
+			if err != nil {
+				return req.Reply(err.Error())
+			}
+			if strings.TrimSpace(answer) == "" {
+				return req.Reply(emptyAnswerMsg)
+			}
+
+			return req.Reply(answer)
+		},
+	}
+}
+
+func sideQuestionText(input string) string {
+	input = strings.TrimSpace(input)
+	if input == "" {
+		return ""
+	}
+	parts := strings.Fields(input)
+	if len(parts) < 2 {
+		return ""
+	}
+	if !strings.HasPrefix(input, parts[0]) {
+		return ""
+	}
+	return strings.TrimSpace(input[len(parts[0]):])
+}