add-function-examples

## Adding Function Examples Review the changes in the current branch, and identify new or modified behavior that would benefit from a reusable example in the `examples/ai-functions` directory. These examples are used for testing specific features against the actual provider APIs, and can also serve as documentation for users. For bug reproductions, follow the [bug-fix workflow in AGENTS.md](../../AGENTS.md#bug-fixes): reproduce the failure end-to-end with a temporary script outside the checkout, then rerun it to verify the fix. Build and use the checkout's local packages for both runs. Publish reproduction-only code **only in the PR description's End-to-End Verification section**, in a collapsible `<details>` block with the complete runnable script, commands, and observed before/after results, following `.github/pull_request_template.md`. **Never commit reproduction-only files**, including under `examples/ai-functions` or elsewhere in the repository. Regression tests and reusable examples that demonstrate supported usage (including fixed behavior) still belong in the repository. Place reusable examples under `examples/ai-functions/src/<function>/<provider>/`, such as `examples/ai-functions/src/stream-text/openai/tool-call.ts`. Use `basic.ts` for the provider entry example and descriptive `kebab-case.ts` names for additional examples. Do not create flat provider files such as `src/stream-text/openai.ts`. Determine for which kind of model and top-level function the example should be added. For a language model, the example should be added in two variants, one for `generateText` and one for `streamText`. For any other models kinds, add the example for the relevant top-level function (e.g. `generateImage`, `generateSpeech`). After creating the example, run `pnpm type-check:full`; fix any errors encountered.