Fix form keyboard issues and sticky footers in agent screens

src/services/security/sessionManager.ts

@@ -0,0 +1,17 @@
+import { appConfig } from '../../config/appConfig';
+
+let lastActivityAt = Date.now();
+
+export const sessionManager = {
+  touch() {
+    lastActivityAt = Date.now();
+  },
+
+  getIdleDurationMs() {
+    return Date.now() - lastActivityAt;
+  },
+
+  hasExpired() {
+    return this.getIdleDurationMs() >= appConfig.security.sessionTimeoutMs;
+  },
+};