Add bootc CI workflow and Dockerfile

- Create Dockerfile for building bootc with Rust and OSTree support
- Add comprehensive CI workflow based on bootupd-sdboot pattern
- Includes apt-cacher-ng support for faster builds
- Builds bootc from composefs-backend branch
- Creates Debian package with proper dependencies
- Uploads to Forgejo Debian Registry
- Uses docker cp to transfer files from container to host
- Includes all three bootc binaries: bootc, system-reinstall-bootc, bootc-initramfs-setup

README.md

@@ -0,0 +1,54 @@
+# Bootc CI/CD Pipeline
+
+This repository contains the CI/CD pipeline for building and packaging `bootc` - a tool for deploying and managing bootable container images.
+
+## What's Included
+
+- **Dockerfile**: Builds bootc with Rust toolchain and OSTree support
+- **CI Workflow**: Complete CI/CD pipeline that:
+  - Builds bootc from source (composefs-backend branch)
+  - Creates Debian packages
+  - Uploads to Forgejo Debian Registry
+  - Uses apt-cacher-ng for faster builds
+
+## Features
+
+- ✅ **Source Build**: Builds bootc from GitHub source (composefs-backend branch)
+- ✅ **Debian Packaging**: Creates proper .deb packages
+- ✅ **OSTree Integration**: Includes OSTree support for atomic updates
+- ✅ **Composefs Backend**: Uses composefs backend for efficient storage
+- ✅ **Registry Upload**: Automatically uploads to Forgejo
+- ✅ **Caching**: Uses apt-cacher-ng for faster builds
+- ✅ **Docker Integration**: Uses Docker for isolated builds
+
+## Binaries Included
+
+- `bootc` - Main bootc command
+- `system-reinstall-bootc` - System reinstall utility
+- `bootc-initramfs-setup` - Initramfs setup tool
+
+## Usage
+
+The CI workflow will automatically:
+1. Clone the bootc source code from composefs-backend branch
+2. Build it with Rust cargo
+3. Create a Debian package
+4. Upload to the Forgejo Debian Registry
+
+## Dependencies
+
+- `libc6 (>= 2.39)`
+- `libgcc-s1 (>= 3.0)`
+- `libssl3t64 (>= 3.0.0)`
+- `libostree-1-1 (>= 2023.1)`
+
+## Installation
+
+Once the CI runs successfully, install with:
+```bash
+apt install bootc
+```
+
+## Branch
+
+This CI builds from the `composefs-backend` branch, which includes composefs support for efficient container image management.