Guard ultrawork variant overrides with SDK metadata

Ultrawork now checks provider SDK metadata before forcing a variant, so unsupported variants are skipped instead of being written into the message state.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/plugin/chat-message.ts

@@ -158,6 +158,13 @@ export function createChatMessageHandler(args: {
       }
     }
 
-    applyUltraworkModelOverrideOnMessage(pluginConfig, input.agent, output, pluginContext.client.tui, input.sessionID)
+    await applyUltraworkModelOverrideOnMessage(
+      pluginConfig,
+      input.agent,
+      output,
+      pluginContext.client.tui,
+      input.sessionID,
+      pluginContext.client,
+    )
   }
 }