feat: add CORE_PLUGINS hook and bundle the notifications tray

[arbrandes]

Description

Ports tutor-contrib-platform-notifications into tutor-mfe so that enabling the plugin gives operators the notifications tray out of the box, with no extra plugin to install.

To support this cleanly, it introduces a CORE_PLUGINS filter in tutormfe.hooks: a registry of bundled frontend plugin packages that ship enabled by default. Operators can disable any core plugin by popping its entry from the filter, symmetrically to how MFE_APPS works today. Notifications is the first (and currently only) core plugin.

Testing

With this branch installed and tutor-mfe enabled, run tutor config save and inspect the rendered environment. In $(tutor config printroot)/env/plugins/mfe/build/mfe/Dockerfile each MFE stage should contain a RUN ... npm install ... @edx/frontend-plugin-notifications@^2.0.3 line just before the mfe-dockerfile-post-npm-install patch call. In $(tutor config printroot)/env/plugins/mfe/build/mfe/env.config.jsx there should be a const { NotificationsTray } = await import('@edx/frontend-plugin-notifications'); line inside the try {} block. In $(tutor config printroot)/env/apps/openedx/settings/lms/production.py, both MFE_CONFIG["SHOW_EMAIL_CHANNEL"] and MFE_CONFIG["SHOW_PUSH_CHANNEL"] should be set, and NOTIFICATIONS_DEFAULT_FROM_EMAIL should be defined via ENV_TOKENS.

To verify the disable path, create a file at $(tutor plugins printroot)/disable_notifications.py containing:

from tutormfe.hooks import CORE_PLUGINS


@CORE_PLUGINS.add()
def _disable_notifications(plugins):
    plugins.pop("notifications", None)
    return plugins

Then run tutor plugins enable disable_notifications && tutor config save. The rendered Dockerfile, env.config.jsx, LMS production settings, and lms-env should no longer reference frontend-plugin-notifications, NotificationsTray, SHOW_EMAIL_CHANNEL, or NOTIFICATIONS_DEFAULT_FROM_EMAIL. Running tutor plugins disable disable_notifications && tutor config save brings them all back.

LLM usage notice

Built with assistance from Claude.

[Faraz32123]

can we add this to mfe-env-config-runtime-definitions patch again like it was in tutor-contrib-platform-notifications instead of filling in env.config.jsx?

[arbrandes]

We could, but not cleanly: the patches tutor-mfe defines (such as mfe-env-config-runtime-definitions) are meant for other plugins to consume. That's what the templates are for: we put the stuff we own in there, and patches are for external use.

[Faraz32123]

can we also move this to plugin.py file under notifications section? As I was thinking we might end up adding plugin slots directly to env.config.jsx in future? Although its also fine if we don't do it.

[arbrandes]

I actually tried, but it doesn't work well: we're consuming the hook (PLUGIN_SLOTS) we're defining ourselves, so there are timing/race conditions that result in the core plugin not being picked up here.

I know it looks funny, but defining this directly in the template is the right place.

[Faraz32123]

there are timing/race conditions that result in the core plugin not being picked up here.

I know it looks funny, but defining this directly in the template is the right place.

makes sense,

[Faraz32123]

@arbrandes Do we need this PR? as most of these changes also exists in frontend-base PR e.g. NOTIFICATIONS_DEFAULT_FROM_EMAIL exists in both, hooks(CORE_PLUGINS & CORE_PLUGIN_ATTRS_TYPE also seems redundant & exists with different names in frontend-base PR) etc.

[arbrandes]

@Faraz32123, we do need this PR. It looks similar to frontend-base, but frontend-plugin-notifications and frontend-app-notifications are two separate things: the first is for legacy MFEs (which this PR takes care of), the second for frontend-base apps.

Once this PR merges, I'll have to rebase the frontend-base one so the two conditions are checked (is_core_plugin_enabled("notifications") and is_frontend_app_enabled("notifications"), for the backend stuff.

(Yes, this looks pretty redundant, but until all MFEs are converted to apps, we're going to have to live with some duplication.)

[Faraz32123]

LGTM!