wikipedia: example fails go vet on unkeyed SearchRequest literal

## Description

The Wikipedia example constructs the exported `wikipedia.SearchRequest` type with an unkeyed struct literal:

```go
wikipedia.SearchRequest{"bytedance"}
```

On current `main` (`6752ff8da9b1ea85c8e91b27b0a64fef099f22f9`), the repository's documented vet check reports:

```text
components/tool/wikipedia/examples/main.go:49:32: wikipedia.SearchRequest struct literal uses unkeyed fields
```

Because the type belongs to another package, the unkeyed literal also couples the example to field order and will silently target the wrong field if fields are reordered.

## Reproduction

From `components/tool/wikipedia` with Go 1.25.6 on Linux:

```text
go vet ./...
```

## Expected behavior

The example should pass `go vet` and name the request field explicitly.

## Suggested fix

Use `wikipedia.SearchRequest{Query: "bytedance"}`.

Open components/tool/wikipedia/examples/main.go and inspect the SearchRequest construction around line 49. Run go vet ./... from components/tool/wikipedia, update the example so the request field is named explicitly, and confirm that the vet check passes.

Written by the indexing model from the issue text.