feat(vision): add vision chat mode

- Add new "vision" chat mode to the application
- Implement the `visionChatMode` function to handle vision-based chat interactions
- Update the UI to include a new button to toggle the vision chat mode
- Add new translations for the "vision" chat mode tooltip
- Disable certain UI elements when the vision chat mode is active

src/assets/locale/en/playground.json

@@ -23,7 +23,8 @@
         "speechToText": "Speech to Text",
         "uploadImage": "Upload Image",
         "stopStreaming": "Stop Streaming",
-        "knowledge": "Knowledge"
+        "knowledge": "Knowledge",
+        "vision": "[Experimental] Vision Chat"
     },
     "sendWhenEnter": "Send when Enter pressed",
     "welcome": "Hello! How can I help you today?"