feat: add embedding config for rag

docs/pg-vector-db-init.md

@@ -60,3 +60,17 @@ psql postgres://shenlan:<密码>@127.0.0.1:5432/mydb -c "\d+ documents"
 若能看到 `embedding | vector(1536)` 字段，说明 pgvector 已成功启用。
 
 完成以上步骤后，应用即可通过连接串 `postgres://shenlan:<密码>@127.0.0.1:5432/mydb` 使用数据库。
+
+## 6. 配置嵌入服务
+
+在 `server/config/server.yaml` 中新增 `embedding` 配置，使服务端能够对问题进行向量化检索：
+
+```yaml
+global:
+  embedding:
+    base_url: http://127.0.0.1:11434
+    token: ""
+    dimension: 1536
+```
+
+其中 `dimension` 需与所使用的嵌入模型返回的向量维度一致。

internal/rag/config/runtime.go

@@ -82,6 +82,11 @@ type Runtime struct {
 	VectorDB    VectorDB     `yaml:"vectordb"`
 	Datasources []DataSource `yaml:"datasources"`
 	Proxy       string       `yaml:"proxy"`
+	Embedding   struct {
+		BaseURL   string `yaml:"base_url"`
+		Token     string `yaml:"token"`
+		Dimension int    `yaml:"dimension"`
+	} `yaml:"embedding"`
 }
 
 // ServerConfigPath points to the server configuration file.
@@ -112,5 +117,8 @@ func (rt *Runtime) ToConfig() *Config {
 	c.Global.VectorDB = rt.VectorDB
 	c.Global.Datasources = rt.Datasources
 	c.Global.Proxy = rt.Proxy
+	c.Embedding.BaseURL = rt.Embedding.BaseURL
+	c.Embedding.Token = rt.Embedding.Token
+	c.Embedding.Dimension = rt.Embedding.Dimension
 	return &c
 }

internal/rag/config/runtime_test.go

@@ -45,3 +45,20 @@ func TestResolveChunking(t *testing.T) {
 		t.Fatalf("expected default slices")
 	}
 }
+
+func TestRuntimeToConfigEmbedding(t *testing.T) {
+	rt := &Runtime{}
+	rt.Embedding.BaseURL = "http://localhost:8080"
+	rt.Embedding.Token = "tok"
+	rt.Embedding.Dimension = 123
+	cfg := rt.ToConfig()
+	if cfg.Embedding.BaseURL != "http://localhost:8080" {
+		t.Fatalf("unexpected base url %q", cfg.Embedding.BaseURL)
+	}
+	if cfg.Embedding.Token != "tok" {
+		t.Fatalf("unexpected token %q", cfg.Embedding.Token)
+	}
+	if cfg.Embedding.Dimension != 123 {
+		t.Fatalf("unexpected dimension %d", cfg.Embedding.Dimension)
+	}
+}

server/config/server.yaml

@@ -6,6 +6,10 @@ global:
   vectordb:
     pgurl: postgres://user:password@127.0.0.1:5432/postgres
   datasources: []
+  embedding:
+    base_url: http://127.0.0.1:11434
+    token: ""
+    dimension: 1536
 api:
   askai:
     timeout: 100