feat: qwinsta/logoff buttons on events list and detail (0.20.4)

RDG flap actions were only on the dashboard; add shared composable and
modal so operators can reset stuck sessions from События and event detail.

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 = "0.20.1";
+export const APP_VERSION = "0.20.4";
 export const APP_VERSION_LABEL = `${APP_NAME} v.${APP_VERSION}`;