refactor: 简化热词配置为豆包控制台 ID

- 移除本地热词列表配置，改为直接使用豆包控制台的热词表 ID
- 删除 internal/asr/hotwords.go（不再需要本地解析）
- 简化 client.go 逻辑，直接传递 boosting_table_id
- 移除 protocol.go 中的 boosting_table_name 字段
- 更新配置示例，添加控制台链接说明

使用方法：
1. 在豆包控制台创建热词表：https://console.volcengine.com/speech/hotword
2. 复制热词表 ID 到 config.yaml 的 boosting_table_id 字段

internal/asr/client.go

@@ -20,10 +20,10 @@ const (
 
 // Config holds Doubao ASR connection parameters.
 type Config struct {
-	AppID       string
-	AccessToken string
-	ResourceID  string
-	Hotwords    []string // 热词列表，格式 "词|权重" 或 "词"
+	AppID            string
+	AccessToken      string
+	ResourceID       string
+	BoostingTableID  string // 热词表 ID（从控制台创建）
 }
 
 // Client manages a single ASR session with Doubao.
@@ -58,21 +58,6 @@ func Dial(cfg Config, resultCh chan<- wsMsg.ServerMsg) (*Client, error) {
 		closeCh: make(chan struct{}),
 		log:     slog.With("conn_id", connID),
 	}
-	// Parse hotwords configuration
-	var boostingTableName string
-	if len(cfg.Hotwords) > 0 {
-		entries, err := ParseHotwords(cfg.Hotwords)
-		if err != nil {
-			slog.Warn("invalid hotwords config, skipping", "err", err)
-		} else {
-			boostingTableName = GenerateTableName(entries)
-			tableContent := FormatHotwordsTable(entries)
-			slog.Info("hotwords enabled",
-				"count", len(entries),
-				"table_name", boostingTableName,
-				"content", tableContent)
-		}
-	}
 	// Send FullClientRequest
 	req := &FullClientRequest{
 		User: UserMeta{UID: connID},
@@ -84,15 +69,15 @@ func Dial(cfg Config, resultCh chan<- wsMsg.ServerMsg) (*Client, error) {
 			Channel: 1,
 		},
 		Request: RequestMeta{
-			ModelName:          "seedasr-2.0",
-			EnableITN:          true,
-			EnablePUNC:         true,
-			EnableDDC:          true,
-			ShowUtterances:     true,
-			ResultType:         "full",
-			EnableNonstream:    true,
-			EndWindowSize:      800,
-			BoostingTableName:  boostingTableName,
+			ModelName:         "seedasr-2.0",
+			EnableITN:         true,
+			EnablePUNC:        true,
+			EnableDDC:         true,
+			ShowUtterances:    true,
+			ResultType:        "full",
+			EnableNonstream:   true,
+			EndWindowSize:     800,
+			BoostingTableID:   cfg.BoostingTableID,
 		},
 	}
 	data, err := EncodeFullClientRequest(req)