feat(通知): SafeW 只发正文并注入推送时间

去掉渠道标题前缀，模板可用 pushedAt 显示本地推送时间。

internal/adapter/safew.go

@@ -53,7 +53,7 @@ func (s *SafeWSender) Send(title, content string, config json.RawMessage) error
 
 	payload := safewMessage{
 		ChatID: chatID,
-		Text:   title + "\n" + content,
+		Text:   content,
 	}
 	body, err := json.Marshal(payload)
 	if err != nil {

internal/adapter/safew_test.go

@@ -49,7 +49,7 @@ func TestSafeWSenderSendSuccess(t *testing.T) {
 	if gotBody["parse_mode"] != nil && gotBody["parse_mode"] != "" {
 		t.Fatalf("parse_mode = %#v, want omitted/plain", gotBody["parse_mode"])
 	}
-	wantText := "hello_world.\nprice=1.5"
+	wantText := "price=1.5"
 	if gotBody["text"] != wantText {
 		t.Fatalf("text = %#v, want %#v", gotBody["text"], wantText)
 	}