Go: add cli command, list dataset documents (#14948)

### What problem does this PR solve?
```
+---------------------+----------------------------------+-------------+-----------------+---------+--------+------+
| created_at          | id                               | meta_fields | name            | size    | status | type |
+---------------------+----------------------------------+-------------+-----------------+---------+--------+------+
| 2026-05-08 19:35:08 | f6aa38bb4ad111f1ba6338a74640adcc | map[]       |  abc.pdf        | 3387987 | 1      | pdf  |
+---------------------+----------------------------------+-------------+-----------------+---------+--------+------+
```

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

internal/cli/user_command.go

@@ -391,7 +391,63 @@ func (c *RAGFlowClient) ListDatasets(cmd *Command) (ResponseIf, error) {
 
 	var result CommonResponse
 	if err = json.Unmarshal(resp.Body, &result); err != nil {
-		return nil, fmt.Errorf("list users failed: invalid JSON (%w)", err)
+		return nil, fmt.Errorf("list datasets failed: invalid JSON (%w)", err)
+	}
+
+	if result.Code != 0 {
+		return nil, fmt.Errorf("%s", result.Message)
+	}
+	result.Duration = resp.Duration
+
+	return &result, nil
+}
+
+// ListDatasetDocumentUserCommand lists dataset documents
+func (c *RAGFlowClient) ListDatasetDocumentUserCommand(cmd *Command) (ResponseIf, error) {
+	if c.ServerType != "user" {
+		return nil, fmt.Errorf("this command is only allowed in USER mode")
+	}
+
+	// Check for benchmark iterations
+	iterations := 1
+	if val, ok := cmd.Params["iterations"].(int); ok && val > 1 {
+		iterations = val
+	}
+
+	// Determine auth kind based on whether API token is being used
+	if c.HTTPClient.LoginToken == "" && !c.HTTPClient.useAPIToken {
+		return nil, fmt.Errorf("no authorization")
+	}
+
+	datasetID, ok := cmd.Params["dataset_id"].(string)
+	if !ok {
+		return nil, fmt.Errorf("no dataset id")
+	}
+
+	page := 1
+	pageSize := 10
+	keywords := ""
+	returnEmptyMetadata := "true"
+	url := fmt.Sprintf("/datasets/%s/documents?page=%d&page_size=%d&keywords=%s&return_empty_metadata=%s", datasetID, page, pageSize, keywords, returnEmptyMetadata)
+
+	if iterations > 1 {
+		// Benchmark mode - return raw result for benchmark stats
+		return c.HTTPClient.RequestWithIterations("GET", url, "web", nil, nil, iterations)
+	}
+
+	// Normal mode
+	resp, err := c.HTTPClient.Request("GET", url, "web", nil, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to list documents: %w", err)
+	}
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("failed to list documents: HTTP %d, body: %s", resp.StatusCode, string(resp.Body))
+	}
+
+	var result ListDocumentsResponse
+	if err = json.Unmarshal(resp.Body, &result); err != nil {
+		return nil, fmt.Errorf("list documents failed: invalid JSON (%w)", err)
 	}
 
 	if result.Code != 0 {