feat: 集成Eino文档解析与嵌入功能

新增Eino相关依赖，支持docx、pdf、xlsx等格式的文档加载与解析，并集成了Dashscope嵌入模型。同时修复了部分DAO查询中的OmitEmpty配置。

rag/eino/document_loader.go

@@ -0,0 +1,51 @@
+package eino
+
+import (
+	"context"
+	"fmt"
+
+	"gitea.com/red-future/common/utils"
+	"github.com/cloudwego/eino-ext/components/document/loader/url"
+	"github.com/cloudwego/eino-ext/components/document/parser/docx"
+	"github.com/cloudwego/eino-ext/components/document/parser/pdf"
+	"github.com/cloudwego/eino-ext/components/document/parser/xlsx"
+	"github.com/cloudwego/eino/components/document"
+	"github.com/cloudwego/eino/components/document/parser"
+	"github.com/cloudwego/eino/schema"
+)
+
+// LoadDocument 业务函数：加载文件
+func LoadDocument(ctx context.Context, filePath, fileFormat string) (docs []*schema.Document, err error) {
+	p, err := docsParser(ctx, fileFormat)
+	if err != nil {
+		return
+	}
+	loader, err := url.NewLoader(ctx, &url.LoaderConfig{
+		Parser: p,
+	})
+	imageUrl, err := utils.GetFileAddressPrefix(ctx)
+	if err != nil {
+		return
+	}
+	docs, err = loader.Load(context.Background(), document.Source{
+		URI: fmt.Sprintf("%s%s", imageUrl, filePath),
+	})
+	return
+}
+
+func docsParser(ctx context.Context, fileFormat string) (p parser.Parser, err error) {
+	switch fileFormat {
+	case "docx":
+		p, err = docx.NewDocxParser(ctx, &docx.Config{
+			ToSections:     true,
+			IncludeHeaders: true,
+			IncludeFooters: true,
+			IncludeTables:  true,
+		})
+	case "pdf":
+		p, err = pdf.NewPDFParser(ctx, &pdf.Config{})
+	case "xlsx":
+		p, err = xlsx.NewXlsxParser(ctx, &xlsx.Config{})
+	}
+	return
+}