Backend: Feature flag for courses based on content availability

[rtibbles]

❌ This issue is not open for contribution. Visit Contributing guidelines to learn about the contributing process and how to find suitable issues.

Overview

Implement a soft feature flag for course functionality by checking if any courses exist on the device. This enables the courses feature only when course content is available.

Implementation

Add to Coach Plugin Data

File: kolibri/plugins/coach/kolibri_plugin.py

Add a courses_exist check similar to the existing practice_quizzes_exist:

from le_utils.constants import modalities

@register_hook
class CoachAsset(webpack_hooks.WebpackBundleHook):
    bundle_id = "app"

    @property
    def plugin_data(self):
        from kolibri.core.content.models import ContentNode

        practice_quizzes_exist = ContentNode.objects.filter(
            available=True, options__contains='"modality": "QUIZ"'
        ).exists()
        
        courses_exist = ContentNode.objects.filter(
            available=True, modality=modalities.COURSE
        ).exists()
        
        return {
            "practice_quizzes_exist": practice_quizzes_exist,
            "courses_exist": courses_exist,
        }

Note: The practice_quizzes_exist check will be updated to use the modality field in issue #13267.

Benefits

• Automatic enablement: Courses feature appears when course content is imported
• No configuration needed: Works automatically based on content availability
• Performant: Uses indexed modality field for O(log n) check
• Consistent pattern: Follows existing practice_quizzes_exist approach

Frontend Integration

The courses_exist value will be available in the frontend via plugin data and can be used to conditionally show/hide the courses tab.