Add HaystackResource

[mathislucka]

We want to add a HaystackServiceResource to our api SDK.

The HaystackServiceResource only has a single method called get_component_schema.

This method should fetch the schema:

curl --request GET
--url 'https://api.cloud.deepset.ai/api/v1/haystack/components?domain=deepset-cloud'
--header 'accept: application/json'

This will return a dict[str, Any] if successful.

Steps

• check src/deepset_mcp/api/pipeline/resource.py and implement the haystack service resource in the same pattern
• create the same folder structure (e.g. ../api/haystack_service/resource.py)
• look at ../api/protocols.py and create a similar protocol for the HaystackService there
• add a haystack_service method to the client in ../api/client.py, in this case we don't need the workspace
• extend the AsyncClientProtocol and add the haystack_service method
• create unit tests for the haystack service resource (look at test/unit for reference)