Open WebUI: Users denied the image-generation permission can still generate images via chat completions

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.7.0 until 0.11.0, the legacy chat-completions features block trusted a client-supplied image_generation flag and did not re-check the features.image_generation permission that the direct image routes and native function-calling path enforce. An authenticated user whose image-generation permission had been revoked could still consume the operator's configured image provider through chat completions, spending API credits and provider quota and writing generated files to operator storage, without exposing provider credentials or other users' data. This issue is fixed in 0.11.0.