Add support for image input in model resources and enhance related configurations

- Introduce a new `support_image_input` field in model resources, allowing models to indicate support for image input.
- Update the backend models, schemas, and database seed scripts to accommodate the new field.
- Enhance the AssistantConfig and related routes to handle image input capabilities, ensuring proper validation and error handling.
- Modify the frontend components to include toggles for enabling visual understanding and filtering models based on image input support.
- Implement necessary adjustments in the voice preview and pipeline to integrate video stream handling alongside audio functionalities.

backend/db/models.py

@@ -50,6 +50,7 @@ class ModelResource(Base):
     )
     values: Mapped[dict] = mapped_column(JSONB, default=dict)
     secrets: Mapped[dict] = mapped_column(JSONB, default=dict)
+    support_image_input: Mapped[bool] = mapped_column(Boolean, default=False)
     enabled: Mapped[bool] = mapped_column(Boolean, default=True)
     is_default: Mapped[bool] = mapped_column(Boolean, default=False)
     created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())