feat: add lockscreen example

lockscreen/AuthContext.qml

@@ -0,0 +1,43 @@
+import QtQuick
+import Quickshell
+import Quickshell.Io
+
+QtObject {
+	property int status: AuthContext.Status.FirstLogin
+	signal unlocked();
+
+	enum Status {
+		FirstLogin,
+		Authenticating,
+		LoginFailed
+	}
+
+	property string password
+
+	property var pamtester: Process {
+		property bool failed: true
+
+		command: ["pamtester", "login", Quickshell.env("USER"), "authenticate"]
+
+		onStarted: this.write(`${password}\n`)
+
+		stdout: SplitParser {
+			// fails go to stderr
+			onRead: pamtester.failed = false
+		}
+
+		onExited: {
+			if (failed) {
+				status = AuthContext.Status.LoginFailed;
+			} else {
+				unlocked();
+			}
+		}
+	}
+
+	function tryLogin(password: string) {
+		this.password = password
+		status = AuthContext.Status.Authenticating;
+		pamtester.running = true;
+	}
+}