feat(campaigns): add get_campaign_timeline service function

backend/app/services/campaign_crud_service.py

@@ -26,6 +26,9 @@ from app.domain.errors import (
 # Import Campaign, CampaignModificationRequest, CampaignTest from app.models.campaign
 from app.models.campaign import Campaign, CampaignModificationRequest, CampaignTest
 
+# Import AuditLog from app.models.audit
+from app.models.audit import AuditLog
+
 # Import Technique from app.models.technique
 from app.models.technique import Technique
 
@@ -1133,3 +1136,31 @@ def list_modification_requests(
         query = query.filter(CampaignModificationRequest.status == status)
     requests = query.order_by(CampaignModificationRequest.created_at.desc()).all()
     return [serialize_modification_request(db, r) for r in requests]
+
+
+def get_campaign_timeline(db: Session, campaign_id: str) -> list[dict]:
+    """Return the chronological audit-log history for a campaign.
+
+    Raises EntityNotFoundError if the campaign does not exist.
+    """
+    campaign = db.query(Campaign).filter(Campaign.id == uuid.UUID(campaign_id)).first()
+    if not campaign:
+        raise EntityNotFoundError("Campaign", campaign_id)
+
+    logs = (
+        db.query(AuditLog)
+        .filter(AuditLog.entity_type == "campaign", AuditLog.entity_id == str(campaign_id))
+        .order_by(AuditLog.timestamp.asc())
+        .all()
+    )
+
+    return [
+        {
+            "id": str(log.id),
+            "action": log.action,
+            "user_id": str(log.user_id) if log.user_id else None,
+            "timestamp": log.timestamp.isoformat() if log.timestamp else None,
+            "details": log.details or {},
+        }
+        for log in logs
+    ]