feat(notifications): trigger notifications on follow, message, and ap…

[GitGuru-sudo]

Pull Request

Summary

Wire the existing create_notification service into real application events (follow, message, application create/accept/reject) so notifications work end-to-end, synchronously. Adds the missing notification Pydantic schema and a NotificationService.notify helper with a self-notification guard.

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Related Issue

Part of #161 (ECSoC 2026)

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Type of Change

• Bug fix
• New feature
• Documentation update
• Performance improvement
• Refactoring
• UI/UX enhancement
• Tests
• Other

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Changes Made

• Create backend/app/schemas/notification.py — was missing, imported by existing router and service
• Add notify() static method to NotificationService — never notifies the actor, never breaks the primary action
• Wire follow_user → FOLLOW notification to the followed user
• Wire send_message → MESSAGE notification to all other conversation members
• Wire create_application → APPLICATION notification to the project owner
• Wire accept_application / reject_application → APPLICATION_ACCEPTED / APPLICATION_REJECTED to the applicant (added current_user dependency to both endpoints)
• Create backend/tests/test_notifications_events.py — 3 tests

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Screenshots (if applicable)

N/A — backend-only change.

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Testing

• Tested locally
• Existing tests pass
• Added new tests
• UI verified
• Cross-browser tested (if applicable)

Additional testing notes: Tested with SQLite in-memory via TestClient. Celery/Redis async delivery is explicitly deferred to PR 2.

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Checklist

• My code follows the project's coding standards.
• I have tested my changes locally.
• I have updated the documentation where necessary.
• My changes do not introduce new warnings or errors.
• I have reviewed my own code.
• This pull request focuses on a single feature or fix.
• I have linked the related issue.

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Additional Notes

Pre-existing breakage (out of scope): main.py imports three routers that don't exist on disk (builders, builder_flare—singular mismatch, ai). Local stubs were used for testing. Flagged in issue #161.

Event → Notification type map:

Event	Endpoint	Recipient	Type
New follower	POST /followers/{user_id}	followed user	FOLLOW
Message sent	POST /messages/	other conversation members	MESSAGE
New application	POST /applications/	project owner	APPLICATION
Application accepted	PATCH /applications/{id}/accept	applicant	APPLICATION_ACCEPTED
Application rejected	PATCH /applications/{id}/reject	applicant	APPLICATION_REJECTED

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[nensii21]

add screenshots and videos showing what changes have been made and also your CI jobs are failing please update it.

[GitGuru-sudo]

@nensii21 these are seeded data