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

Dockerfile

@@ -0,0 +1,28 @@
+# Build from the current git into a c9s-bootc container image.
+# Use e.g. --build-arg=base=quay.io/fedora/fedora-bootc:41 to target
+# Fedora or another base image instead.
+#
+ARG base=quay.io/centos-bootc/centos-bootc:stream9
+
+FROM $base as build
+# This installs our package dependencies, and we want to cache it independently of the rest.
+# Basically we don't want changing a .rs file to blow out the cache of packages.
+RUN <<EORUN
+set -xeuo pipefail
+dnf -y install cargo git openssl-devel
+EORUN
+# Now copy the source
+COPY . /build
+WORKDIR /build
+# See https://www.reddit.com/r/rust/comments/126xeyx/exploring_the_problem_of_faster_cargo_docker/
+# We aren't using the full recommendations there, just the simple bits.
+RUN --mount=type=cache,target=/build/target --mount=type=cache,target=/var/roothome \
+    make && make install-all DESTDIR=/out
+
+FROM $base
+# Clean out the default to ensure we're using our updated content
+RUN rpm -e bootupd
+COPY --from=build /out/ /
+# Sanity check this too
+RUN bootc container lint --fatal-warnings
+