feat: optimize WebUI stream output and sanitize user-facing answers

cmd/bot/main_test.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"testing"
+
+	"laodingbot/internal/agent"
+	"laodingbot/internal/transport/webui"
+)
+
+func TestBuildWebUIStreamForwarderFiltersTraceEvents(t *testing.T) {
+	var got []webui.StreamEvent
+	forwarder := buildWebUIStreamForwarder(func(event webui.StreamEvent) error {
+		got = append(got, event)
+		return nil
+	})
+
+	events := []agent.StreamEvent{
+		{Type: agent.StreamEventTypeThought, Content: "thinking", Step: 1},
+		{Type: agent.StreamEventTypeToolCall, Content: "pwd", Step: 1, ToolName: "shell"},
+		{Type: agent.StreamEventTypeToolResult, Content: "C:/Project", Step: 1, ToolName: "shell"},
+		{Type: agent.StreamEventTypeFinal, Content: "done", Step: 2},
+		{Type: agent.StreamEventTypeError, Content: "boom", Step: 3},
+	}
+
+	for _, event := range events {
+		if err := forwarder(event); err != nil {
+			t.Fatalf("forwarder returned error: %v", err)
+		}
+	}
+
+	if len(got) != 2 {
+		t.Fatalf("expected 2 forwarded events, got %d", len(got))
+	}
+	if got[0].Type != webui.StreamEventTypeFinal || got[0].Content != "done" {
+		t.Fatalf("unexpected final event: %+v", got[0])
+	}
+	if got[0].Step != 0 || got[0].ToolName != "" {
+		t.Fatalf("expected final event without trace fields, got %+v", got[0])
+	}
+	if got[1].Type != webui.StreamEventTypeError || got[1].Content != "boom" {
+		t.Fatalf("unexpected error event: %+v", got[1])
+	}
+}