bypos-collector: 移除硬编码 sdogid、添加重试、补全 CSV 导出、增加测试

改进内容:
- sdogid 不再硬编码，优先从 $BYPOS_SDOGID 环境变量读取，其次 -sdogid 参数，
  也可在 Web 控制台输入框填写；三者都未设时启动警告、采集报错
- 网络错误自动重试（最多 3 次，指数退避 500ms/1s/2s）
- Web 控制台采集参数区增加 sdogid 输入框
- CSV 导出补全 retmsg 和 source 两列
- 新增 Go 单元测试（ean13Check、md5hex、sanitizeBarcodes、resolveSdogID 等）
- README 更新配置说明

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

tools/bypos-collector/main.go

@@ -20,15 +20,16 @@ import (
 //go:embed web/*
 var webFS embed.FS
 
-var collector = NewCollector("")
+var collector *Collector
 
 func main() {
 	addr := flag.String("addr", "127.0.0.1:8765", "本地监听地址")
 	noOpen := flag.Bool("no-open", false, "不自动打开浏览器")
-	sdog := flag.String("sdogid", "", "中心库账号 id(默认使用内置值)")
+	sdog := flag.String("sdogid", "", "中心库账号 id（优先读 $BYPOS_SDOGID 环境变量）")
 	flag.Parse()
-	if *sdog != "" {
-		collector.sdogID = *sdog
+	collector = NewCollector(*sdog)
+	if collector.sdogID == "" {
+		log.Println("警告: 未配置 sdogid，请通过 $BYPOS_SDOGID 环境变量、-sdogid 参数或控制台输入框指定")
 	}
 
 	sub, _ := fs.Sub(webFS, "web")
@@ -143,14 +144,14 @@ func handleExportCSV(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Disposition", "attachment; filename=products.csv")
 	w.Write([]byte{0xEF, 0xBB, 0xBF}) // UTF-8 BOM so Excel reads Chinese correctly
 	cw := csv.NewWriter(w)
-	cw.Write([]string{"barcode", "name", "spec", "unit", "area", "manufacturer", "license", "in_price", "sell_price", "status", "fetched_at"})
+	cw.Write([]string{"barcode", "name", "spec", "unit", "area", "manufacturer", "license", "in_price", "sell_price", "status", "retmsg", "fetched_at", "source"})
 	dec := json.NewDecoder(f)
 	for {
 		var p Product
 		if err := dec.Decode(&p); err != nil {
 			break
 		}
-		cw.Write([]string{p.Barcode, p.Name, p.Spec, p.Unit, p.Area, p.Manufacturer, p.License, p.InPrice, p.SellPrice, p.Status, p.FetchedAt})
+		cw.Write([]string{p.Barcode, p.Name, p.Spec, p.Unit, p.Area, p.Manufacturer, p.License, p.InPrice, p.SellPrice, p.Status, p.RetMsg, p.FetchedAt, p.Source})
 	}
 	cw.Flush()
 }