fix: hide ????????? after session terminate (0.3.8)

Persist session_terminated in event details, expose in API, and update Events/Dashboard UI.

Co-authored-by: Cursor <cursoragent@cursor.com>

README_en.md

@@ -13,7 +13,7 @@ Self-hosted hub for security events from Linux and Windows agents: ingest, corre
 | **security-alert-center** | SAC server (Ubuntu 24.04) |
 | [seaca](https://git.kalinamall.ru/PapaTramp/seaca) | Android client |
 
-**Version:** `0.3.7` · **Deploy:** `sudo /opt/sac-deploy.sh`
+**Version:** `0.3.8` · **Deploy:** `sudo /opt/sac-deploy.sh`
 
 ## Features