feat: parallel agent upgrades with per-host log panels (0.4.2)

Allow multiple remote update jobs at once; each upgrade gets its own
bottom-right log dock that auto-closes 30s after success.

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

frontend/src/version.ts

@@ -1,4 +1,4 @@
 /** Fallback до загрузки /health; при релизе держите в sync с backend/app/version.py */
 export const APP_NAME = "Security Alert Center";
-export const APP_VERSION = "0.4.0";
+export const APP_VERSION = "0.4.2";
 export const APP_VERSION_LABEL = `${APP_NAME} v.${APP_VERSION}`;