Add custom QZ Tray fork with pairing key authentication

- Custom fork of QZ Tray 2.2.x with certificate validation bypassed
- Implemented pairing key (HMAC) authentication as replacement
- Modified files: PrintSocketClient.java (certificate check disabled)
- New files: PairingAuth.java, PairingConfigDialog.java
- Excluded build artifacts (out/, lib/javafx*) from repository
- Library JARs included for dependency management

tray/js/README.md

@@ -0,0 +1,23 @@
+```js
+const qz = require("qz-tray");
+
+qz.websocket.connect().then(() => {
+    return qz.printers.find();
+}).then((printers) => {
+    console.log(printers);
+    let config = qz.configs.create('PDF');
+    return qz.print(config, [{
+        type: 'pixel',
+        format: 'html',
+        flavor: 'plain',
+        data: '<h1>Hello JavaScript!</h1>'
+    }]);
+}).then(() => {
+    return qz.websocket.disconnect();
+}).then(() => {
+    // process.exit(0);
+}).catch((err) => {
+    console.error(err);
+    // process.exit(1);
+});
+```