Add support for interacting with Claude in the assistant panel (#11798)

Release Notes:

- Added support for interacting with Claude in the assistant panel. You
can enable it by adding the following to your `settings.json`:

    ```json
    "assistant": {
        "version": "1",
        "provider": {
            "name": "anthropic"
        }
    }
    ```

crates/assistant/Cargo.toml

@@ -11,6 +11,7 @@ doctest = false
 
 [dependencies]
 anyhow.workspace = true
+anthropic = { workspace = true, features = ["schemars"] }
 chrono.workspace = true
 client.workspace = true
 collections.workspace = true