Broaden UA guidance to "clients" instead of "client SDKs"

Author: LucaButBoring

docs/specification/draft/basic/index.mdx

@@ -201,18 +201,18 @@ Multiple icons can be provided to support different display contexts and resolut
 
 ## User Agents
 
-Client SDK implementations **SHOULD** use the following format by default for their
+Client implementations **SHOULD** use the following format by default for their
 `User-Agent` header when sending HTTP requests:
 
 ```
-SDK_NAME[/SDK_VERSION] [os/PLATFORM[#PLATFORM_RELEASE]] [lang/LANG[#LANG_VERSION]] [md/KEY[#VALUE]]
+CLIENT_NAME[/CLIENT_VERSION] [os/PLATFORM[#PLATFORM_RELEASE]] [lang/LANG[#LANG_VERSION]] [md/KEY[#VALUE]]
 ```
 
-The first component of the user agent contains the SDK name and version, as published
-to package registries. SDK implementations **MAY** use a different product name if
+The first component of the user agent contains any applicable client name and version.
+Client implementations **MAY** use a different product name if
 necessary, to be compliant with [RFC 9110](https://httpwg.org/specs/rfc9110.html#rfc.section.10.1.5).
 The optional `os` component contains the current platform and optional platform
-version. The optional `lang` component contains the SDK programming language and optional
+version. The optional `lang` component contains the client's programming language and optional
 language version. The user agent **MAY** contain one or more `md` components for
 additional metadata, containing a key and an optional value.
 
@@ -224,7 +224,7 @@ my-mcp-sdk/1.0.0 os/win32#10.0.22000 lang/java#21.0.7
 ```
 
 As a more complex example, consider a version `v1.0.0` of `my-mcp-sdk` running on MacOS,
-using Node.js `v22.13.1`. In that scenario, the SDK might have the following user agent:
+using Node.js `v22.13.1`. In that scenario, the client might have the following user agent:
 
 ```
 my-mcp-sdk/1.0.0 os/darwin#24.5.0 lang/js md/nodejs#22.13.1