fix(topology): persist incident before adding alerts (fixes #5463)

[asheeshgupta-devops]

Summary

Fixes ForeignKeyViolation when creating topology-based incidents in the topology processor.

Root Cause

In _create_application_based_incident(), the Incident object was created in memory but not persisted to the database before calling assign_alert_to_incident(). This caused LastAlertToIncident inserts to fail with:

psycopg2.errors.ForeignKeyViolation: insert or update on table "lastalerttoincident" 
violates foreign key constraint "lastalerttoincident_incident_id_fkey"
DETAIL: Key (incident_id)=(...) is not present in table "incident".

The Fix

Add session.add(incident) and session.flush() after creating the Incident object to ensure the incident.id exists in the database before any alert associations are created.

# Before (broken):
incident = Incident(...)
for alert in alerts:
    assign_alert_to_incident(...)  # FAILS - incident.id doesn't exist

# After (fixed):
incident = Incident(...)
session.add(incident)
session.flush()  # Now incident.id exists in DB
for alert in alerts:
    assign_alert_to_incident(...)  # Works!

Changes

• keep/topologies/topology_processor.py - Add session.add() and session.flush() before alert assignment

Testing

• Verified the fix addresses the exact error reported in [🐛 Bug]: Topology Correlation not working #5463
• The same pattern is already used elsewhere in Keep (e.g., manual incident creation)

Fixes #5463
Related to #4816

[vercel]

@asheeshgupta-devops is attempting to deploy a commit to the KeepHQ Team on Vercel.

A member of the Team first needs to authorize it.

[CLAassistant]

All committers have signed the CLA.

[shahargl]

lgtm

[github-actions]

💪 Fantastic work @asheeshgupta-devops! Your very first PR to keep has been merged! 🎉🥳

You've just taken your first step into open-source, and we couldn't be happier to have you onboard. 🙌
If you're feeling adventurous, why not dive into another issue and keep contributing? The community would love to see more from you! 🚀

For any support, feel free to reach out on the community: https://slack.keephq.dev. Happy coding! 👩‍💻👨‍💻