chore: import upstream snapshot with attribution

docs/en/integrations/cloudgda/source.md

@@ -0,0 +1,45 @@
+---
+title: "Gemini Data Analytics Source"
+type: docs
+weight: 1
+linkTitle: "Source"
+description: >
+  A "cloud-gemini-data-analytics" source provides a client for the Gemini Data Analytics API.
+no_list: true
+---
+
+## About
+
+The `cloud-gemini-data-analytics` source provides a client to interact with the [Gemini Data Analytics API](https://docs.cloud.google.com/gemini/docs/conversational-analytics-api/reference/rest). This allows tools to send natural language queries to the API.
+
+Authentication can be handled in two ways:
+
+1.  **Application Default Credentials (ADC) (Recommended):** By default, the source uses ADC to authenticate with the API. The Toolbox server will fetch the credentials from its running environment (server-side authentication). This is the recommended method.
+2.  **Client-side OAuth:** If `useClientOAuth` is set to `true`, the source expects the authentication token to be provided by the caller when making a request to the Toolbox server (typically via an HTTP Bearer token). The Toolbox server will then forward this token to the underlying Gemini Data Analytics API calls.
+
+## Available Tools
+
+{{< list-tools >}}
+
+## Example
+
+```yaml
+kind: source
+name: my-gda-source
+type: cloud-gemini-data-analytics
+projectId: my-project-id
+---
+kind: source
+name: my-oauth-gda-source
+type: cloud-gemini-data-analytics
+projectId: my-project-id
+useClientOAuth: true
+```
+
+## Reference
+
+| **field**      | **type** | **required** | **description**                                                                                                                                                              |
+| -------------- | :------: | :----------: | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| type           |  string  |     true     | Must be "cloud-gemini-data-analytics".                                                                                                                                       |
+| projectId      |  string  |     true     | The Google Cloud Project ID where the API is enabled.                                                                                                                        |
+| useClientOAuth | boolean  |    false     | If true, the source uses the token provided by the caller (forwarded to the API). Otherwise, it uses server-side Application Default Credentials (ADC). Defaults to `false`. |