add linux local build script

scripts/build_package_linux.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+set -euo pipefail
+
+poetry lock
+poetry install
+
+# Build using the Linux spec so the build is reproducible and uses the project spec
+poetry run pyinstaller scripts/spec_scripts/android-file-handler-linux.spec --distpath dist
+
+# Package into a Debian .deb using fpm
+export PATH="$HOME/.local/bin:/usr/local/bin:$PATH"
+VERSION="$(poetry version -s)"
+mkdir -p dist
+chmod +x dist/android-file-handler
+# explicit filename into dist/ (Debian .deb)
+# change directory into dist and package the binary named 'android-file-handler'
+# this ensures the package installs /usr/local/bin/android-file-handler (no extra dist/ prefix)
+
+# Debian
+fpm -s dir -t deb -n android-file-handler -v "$VERSION" \
+--architecture amd64 --prefix /usr/local/bin --deb-user root --deb-group root \
+-p "dist/android-file-handler_${VERSION}_amd64.deb" -C dist android-file-handler