fix: add structured graph tool results

internal/ai/runtime/tooling/tool_result.go

@@ -0,0 +1,42 @@
+package tooling
+
+import (
+	"encoding/json"
+	"strings"
+)
+
+type ToolResult struct {
+	Handled     bool   `json:"handled"`
+	Terminal    bool   `json:"terminal"`
+	Action      string `json:"action"`
+	ReplyText   string `json:"replyText,omitempty"`
+	ReplySent   bool   `json:"replySent,omitempty"`
+	ShouldRetry bool   `json:"shouldRetry"`
+}
+
+func MarshalToolResult(result ToolResult) string {
+	result.Action = strings.TrimSpace(result.Action)
+	result.ReplyText = strings.TrimSpace(result.ReplyText)
+	buf, err := json.Marshal(result)
+	if err != nil {
+		return ""
+	}
+	return string(buf)
+}
+
+func ParseToolResult(raw string) (ToolResult, bool) {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return ToolResult{}, false
+	}
+	var result ToolResult
+	if err := json.Unmarshal([]byte(raw), &result); err != nil {
+		return ToolResult{}, false
+	}
+	result.Action = strings.TrimSpace(result.Action)
+	result.ReplyText = strings.TrimSpace(result.ReplyText)
+	if result.Action == "" && result.ReplyText == "" && !result.Handled && !result.Terminal {
+		return ToolResult{}, false
+	}
+	return result, true
+}