Version: 0.9.65.dev.260503

后端：
1. 阶段 1.5/1.6
收口 llm-service / rag-service，统一模型出口与检索基础设施入口，清退 backend/infra/llm 与 backend/infra/rag 旧实现；
2. 同步更新相关调用链与微服务迁移计划文档

backend/services/rag/config/config.go

@@ -0,0 +1,113 @@
+package config
+
+import "github.com/spf13/viper"
+
+// Config 是 RAG Core 运行配置。
+type Config struct {
+	Enabled bool
+	Store   string
+	TopK    int
+
+	Threshold float64
+
+	EmbedProvider  string
+	EmbedModel     string
+	EmbedBaseURL   string
+	EmbedTimeoutMS int
+	EmbedDimension int
+
+	RerankerEnabled   bool
+	RerankerProvider  string
+	RerankerTimeoutMS int
+
+	ChunkSize    int
+	ChunkOverlap int
+
+	RetrieveTimeoutMS int
+
+	MilvusAddress          string
+	MilvusToken            string
+	MilvusDBName           string
+	MilvusCollectionName   string
+	MilvusMetricType       string
+	MilvusRequestTimeoutMS int
+}
+
+// LoadFromViper 读取 rag 配置并补默认值。
+func LoadFromViper() Config {
+	cfg := Config{
+		Enabled:                viper.GetBool("rag.enabled"),
+		Store:                  viper.GetString("rag.store"),
+		TopK:                   viper.GetInt("rag.topK"),
+		Threshold:              viper.GetFloat64("rag.threshold"),
+		EmbedProvider:          viper.GetString("rag.embed.provider"),
+		EmbedModel:             viper.GetString("rag.embed.model"),
+		EmbedBaseURL:           viper.GetString("rag.embed.baseURL"),
+		EmbedTimeoutMS:         viper.GetInt("rag.embed.timeoutMs"),
+		EmbedDimension:         viper.GetInt("rag.embed.dimension"),
+		RerankerEnabled:        viper.GetBool("rag.reranker.enabled"),
+		RerankerProvider:       viper.GetString("rag.reranker.provider"),
+		RerankerTimeoutMS:      viper.GetInt("rag.reranker.timeoutMs"),
+		ChunkSize:              viper.GetInt("rag.ingest.chunkSize"),
+		ChunkOverlap:           viper.GetInt("rag.ingest.chunkOverlap"),
+		RetrieveTimeoutMS:      viper.GetInt("rag.retrieve.timeoutMs"),
+		MilvusAddress:          viper.GetString("rag.milvus.address"),
+		MilvusToken:            viper.GetString("rag.milvus.token"),
+		MilvusDBName:           viper.GetString("rag.milvus.dbName"),
+		MilvusCollectionName:   viper.GetString("rag.milvus.collectionName"),
+		MilvusMetricType:       viper.GetString("rag.milvus.metricType"),
+		MilvusRequestTimeoutMS: viper.GetInt("rag.milvus.requestTimeoutMs"),
+	}
+	if cfg.Store == "" {
+		cfg.Store = "inmemory"
+	}
+	if cfg.TopK <= 0 {
+		cfg.TopK = 8
+	}
+	if cfg.Threshold < 0 {
+		cfg.Threshold = 0
+	}
+	if cfg.EmbedProvider == "" {
+		cfg.EmbedProvider = "mock"
+	}
+	if cfg.EmbedBaseURL == "" {
+		cfg.EmbedBaseURL = viper.GetString("agent.baseURL")
+	}
+	if cfg.EmbedTimeoutMS <= 0 {
+		cfg.EmbedTimeoutMS = 1200
+	}
+	if cfg.EmbedDimension <= 0 {
+		cfg.EmbedDimension = 1024
+	}
+	if cfg.RerankerProvider == "" {
+		cfg.RerankerProvider = "noop"
+	}
+	if cfg.RerankerTimeoutMS <= 0 {
+		cfg.RerankerTimeoutMS = 1200
+	}
+	if cfg.ChunkSize <= 0 {
+		cfg.ChunkSize = 400
+	}
+	if cfg.ChunkOverlap < 0 {
+		cfg.ChunkOverlap = 80
+	}
+	if cfg.RetrieveTimeoutMS <= 0 {
+		cfg.RetrieveTimeoutMS = 1500
+	}
+	if cfg.MilvusAddress == "" {
+		cfg.MilvusAddress = "http://localhost:19530"
+	}
+	if cfg.MilvusToken == "" {
+		cfg.MilvusToken = "root:Milvus"
+	}
+	if cfg.MilvusCollectionName == "" {
+		cfg.MilvusCollectionName = "smartflow_rag_chunks"
+	}
+	if cfg.MilvusMetricType == "" {
+		cfg.MilvusMetricType = "COSINE"
+	}
+	if cfg.MilvusRequestTimeoutMS <= 0 {
+		cfg.MilvusRequestTimeoutMS = 1500
+	}
+	return cfg
+}