feat: Phase 2 (fragment migration), Phase 3 (testing infrastructure), Phase 4 (CI/CD)

Phase 2: Fragment Migration
- Migrated 42 ingredients to 54 fine-grained fragments
- Replaced %include with %ksappend syntax
- Created organized fragment structure (platform/generic-43, platform/generic-rawhide, shared/)
- Updated generator to use fragment paths
- All 16 manifest variants generate successfully

Phase 3: Testing Infrastructure
- Created containerized test runner (tests/container/)
- Added integration test suite (tests/integration/)
- Created golden master fixtures (tests/fixtures/expected_recipes/)
- 41 tests passing (36 unit + 5 integration)
- 54 fragments, 16 recipes validated

Phase 4: CI/CD Integration
- 5 new workflows: validate-recipes, validate-fragments, test-generation, container-tests, build-iso
- Added validation gates before ISO builds
- Works with existing fedora-runner-image
- Local testing support via act_runner

fragments/shared/hypervisor/intelgpu.ks

@@ -0,0 +1,11 @@
+# Intel GPU passthrough configuration
+
+%post --nochroot --log=/mnt/sysimage/root/hypervisor-intelgpu-post.log # Beginning of %post section. Those commands are executed outside the chroot environment. Logging is enabled to help with post-installtion troubleshooting
+
+sed -i 's/\(vfio-pci\)/\1 i915.enable_gvt=1/i' /mnt/sysimage/etc/default/grub # Load kernel modules in grub.
+
+# Load extra kernel modules to enable vfio-mdev on selected hardware
+echo "kvmgt" > /mnt/sysimage/etc/modules-load.d/kvmgt.conf # Load specific kernel modules kvmgt and vfio-mdev, for Intel (tm) GVT-g and Nvidia (tm)
+echo "vfio-mdev" > /mnt/sysimage/etc/modules-load.d/vfio-mdev.conf # Load specific kernel modules kvmgt and vfio-mdev, for Intel (tm) GVT-g and Nvidia (tm)
+
+%end # End of the %post section