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/Dockerfile

@@ -0,0 +1,14 @@
+FROM openjdk:11 as build
+RUN apt-get update
+RUN apt-get install -y ant nsis makeself
+COPY . /usr/src/tray
+WORKDIR /usr/src/tray
+RUN ant makeself
+
+FROM openjdk:11-jre as install
+RUN apt-get update
+RUN apt-get install -y libglib2.0-bin
+COPY --from=build /usr/src/tray/out/*.run /tmp
+RUN find /tmp -iname "*.run" -exec {} \;
+WORKDIR /opt/qz-tray
+ENTRYPOINT ["/opt/qz-tray/qz-tray"]