…estsRewrote the `AvatarFlair` component using Glimmer, removing legacy `MountWidget` usage.Improved maintainability with helper functions for styles and icon handling.Added integration tests to ensure correct rendering for icon and image flair scenarios.

Refactored `POST_STREAM_DEPRECATION_OPTIONS` and other deprecation logic into `widget.js` for consistent handling across the codebase. Introduced `warnWidgetsDeprecation` to streamline warnings. Updated various widget-related usages and tests to align with the new approach.

…oballyIntroduced the `deactivate_widgets_rendering` site setting to allow global deactivation of widget rendering. Updated `createWidget`, `MountWidget`, and `registerWidgetShim` to respect this setting by halting execution if widgets are deactivated. Added checks and logic across relevant components to ensure smooth behavior when widgets are turned off.

Updated the default configuration of the `deactivate_widgets_rendering` site setting from "yes" to "no".

Updated the `deactivate_widgets_rendering` site setting to use a boolean instead of an enum. Adjusted related logic in `createWidget`, `MountWidget`, and `registerWidgetShim` to align with this change. Simplified configuration in `site_settings.yml` by replacing choices with a default `false`.

…localizationChanged the default value of `deactivate_widgets_rendering` to `true` in `site_settings.yml` and added a corresponding localization string to `server.en.yml`. This aligns with ongoing efforts to phase out legacy widget rendering.

…er_post_stream`Updated the `deactivate_widgets_rendering` setting to unconditionally enable the Glimmer Post Stream regardless of the `glimmer_post_stream_mode` setting. Adjusted related logic in the `site` model and updated the localization string for clarity.