Add multi-distribution ostree backport support for Ubuntu Noble and Debian Trixie

- Add main ostree-backport.sh script with distribution selection
- Add wrapper scripts: backport-noble.sh and backport-trixie.sh
- Add usage-guide.sh for comprehensive documentation
- Update CI/CD workflows with improved multi-distribution support
- Add test-build.yml workflow for quick validation
- Update README.md with multi-distribution documentation
- Add CI-CD-IMPROVEMENTS.md with detailed workflow documentation
- Remove old .deb files (steam.deb, wget_1.21.4-1ubuntu4.1_amd64.deb)

Features:
- Ubuntu Noble: Source from Questing, target Noble
- Debian Trixie: Source from sid, target Trixie
- Enhanced error handling and logging
- Manual triggers for single/all distributions
- Comprehensive CI/CD documentation

usage-guide.sh

@@ -0,0 +1,75 @@
+#!/bin/bash
+
+# Usage Guide for ostree Backport System
+# This script provides information about the multi-distribution backport system
+
+echo "=== ostree Backport System Usage Guide ==="
+echo ""
+
+echo "🎯 Supported Distributions:"
+echo "   • Ubuntu Noble (24.04 LTS) - Source: Ubuntu Questing"
+echo "   • Debian Trixie (12) - Source: Debian sid"
+echo ""
+
+echo "📦 Available Scripts:"
+echo "   • ostree-backport.sh [distro] - Main backport script"
+echo "   • backport-noble.sh - Ubuntu Noble wrapper"
+echo "   • backport-trixie.sh - Debian Trixie wrapper"
+echo ""
+
+echo "🚀 Quick Start Examples:"
+echo ""
+echo "For Ubuntu Noble:"
+echo "   ./backport-noble.sh"
+echo "   # or"
+echo "   ./ostree-backport.sh noble"
+echo ""
+echo "For Debian Trixie:"
+echo "   ./backport-trixie.sh"
+echo "   # or"
+echo "   ./ostree-backport.sh trixie"
+echo ""
+
+echo "🔧 What Each Script Does:"
+echo "   1. Downloads ostree 2025.2-1 source from appropriate distribution"
+echo "   2. Modifies changelog for backport versioning"
+echo "   3. Installs build dependencies"
+echo "   4. Builds all ostree packages"
+echo "   5. Installs the backported packages"
+echo ""
+
+echo "⚠️  Safety Notes:"
+echo "   • Test in a VM first"
+echo "   • Have a system backup"
+echo "   • Be prepared for potential side effects with Flatpak"
+echo ""
+
+echo "📚 Source References:"
+echo "   • Debian sid: https://packages.debian.org/source/sid/ostree"
+echo "   • Ubuntu Questing: http://archive.ubuntu.com/ubuntu/pool/universe/o/ostree/"
+echo ""
+
+echo "🔗 CI/CD Workflow:"
+echo "   • Automated builds on every push"
+echo "   • Supports both distributions via matrix strategy"
+echo "   • Manual trigger available for specific distributions"
+echo ""
+
+echo "📋 Package Contents:"
+echo "   • libostree-dev - Development headers and libraries"
+echo "   • libostree-1-1 - Runtime libraries"
+echo "   • ostree - Command-line tools"
+echo "   • gir1.2-ostree-1.0 - GObject introspection"
+echo "   • libostree-doc - Documentation"
+echo "   • ostree-boot - Boot utilities"
+echo "   • ostree-tests - Test suite"
+echo ""
+
+echo "✅ Verification:"
+echo "   pkg-config --modversion ostree-1"
+echo "   # Should output: 2025.2"
+echo ""
+
+echo "🔄 Rollback:"
+echo "   sudo apt install --reinstall libostree-dev libostree-1-1 ostree"
+echo "   # Reinstall original packages from distribution repositories"