chore: update OpenAPI spec [sdk-bot]

Author: OpenRouter SDK Bot

.speakeasy/in.openapi.yaml

@@ -10565,6 +10565,10 @@ components:
         stream:
           description: 'If true, partial images are streamed as SSE events as they become available. Only supported by providers with native streaming (currently OpenAI). Non-streaming providers ignore this flag and return a buffered response.'
           type: 'boolean'
+        user:
+          description: 'A stable identifier for your end-users. Used to help detect and prevent abuse. Never sent to providers verbatim: for providers whose data policy requires user IDs, it is folded into a hashed, per-account upstream user identifier.'
+          example: 'end-user-abc123'
+          type: 'string'
       required:
         - 'model'
         - 'prompt'