Restructure project layout for better CI/CD integration

- Flattened nested bootupd/bootupd/ structure to root level
- Moved all core project files to root directory
- Added proper Debian packaging structure (debian/ directory)
- Created build scripts and CI configuration
- Improved project organization for CI/CD tools
- All Rust source, tests, and configuration now at root level
- Added GitHub Actions workflow for automated testing
- Maintained all original functionality while improving structure

systemd/bootloader-update.service

@@ -0,0 +1,16 @@
+[Unit]
+Description=Update bootloader on boot
+Documentation=https://github.com/coreos/bootupd
+
+[Service]
+Type=oneshot
+ExecStart=/usr/bin/bootupctl update
+RemainAfterExit=yes
+# Keep this stuff in sync with SYSTEMD_ARGS_BOOTUPD in general
+PrivateNetwork=yes
+ProtectHome=yes
+KillMode=mixed
+MountFlags=slave
+
+[Install]
+WantedBy=multi-user.target