feat(audit): add audit logging for organization invites

Log ORG_INVITE_SENT action when a user sends an organization invite,
capturing the invited email and role in the audit metadata.

gatehouse_app/api/v1/organizations/invites.py

@@ -8,7 +8,8 @@ from gatehouse_app.services.notification_service import NotificationService
 from gatehouse_app.services.auth_service import AuthService
 from gatehouse_app.services.organization_service import OrganizationService
 from gatehouse_app.services.email_templates import build_org_invite_html
-from gatehouse_app.utils.constants import OrganizationRole
+from gatehouse_app.utils.constants import AuditAction, OrganizationRole
+from gatehouse_app.services.audit_service import AuditService
 
 
 @api_v1_bp.route("/organizations/<org_id>/invites", methods=["POST"])
@@ -56,6 +57,19 @@ def create_org_invite(org_id):
     logging.getLogger(__name__).info(f"[INVITE] Email queued for {email}")
     email_sent = True  # async — assume queued successfully
 
+    AuditService.log_action(
+        action=AuditAction.ORG_INVITE_SENT,
+        user_id=g.current_user.id,
+        organization_id=org_id,
+        resource_type="org_invite",
+        resource_id=invite.id,
+        metadata={
+            "invited_email": email,
+            "role": role,
+        },
+        description=f"Invitation sent to {email} with role {role}",
+    )
+
     response_data = {
         "invite": {
             "id": invite.id,

gatehouse_app/utils/constants.py

@@ -75,6 +75,7 @@ class AuditAction(str, Enum):
     ORG_MEMBER_REMOVE = "org.member.remove"
     ORG_MEMBER_ROLE_CHANGE = "org.member.role_change"
     ORG_OWNERSHIP_TRANSFERRED = "org.ownership.transferred"
+    ORG_INVITE_SENT = "org.invite.sent"
 
     # Session actions
     SESSION_CREATE = "session.create"