Initial commit: OpenRouter Python SDK

Auto-generated Python SDK for OpenRouter API, providing comprehensive client library with:
- Chat completions and streaming support
- Embeddings API
- Model and provider information
- API key management
- Analytics and usage tracking
- OAuth authentication flows
- Full type hints and error handling

docs/models/openresponsesrequesttoolunion.md

@@ -0,0 +1,35 @@
+# OpenResponsesRequestToolUnion
+
+
+## Supported Types
+
+### `models.OpenResponsesRequestToolFunction`
+
+```python
+value: models.OpenResponsesRequestToolFunction = /* values here */
+```
+
+### `models.OpenResponsesWebSearchPreviewTool`
+
+```python
+value: models.OpenResponsesWebSearchPreviewTool = /* values here */
+```
+
+### `models.OpenResponsesWebSearchPreview20250311Tool`
+
+```python
+value: models.OpenResponsesWebSearchPreview20250311Tool = /* values here */
+```
+
+### `models.OpenResponsesWebSearchTool`
+
+```python
+value: models.OpenResponsesWebSearchTool = /* values here */
+```
+
+### `models.OpenResponsesWebSearch20250826Tool`
+
+```python
+value: models.OpenResponsesWebSearch20250826Tool = /* values here */
+```
+