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

tests/integration/conftest.py

@@ -0,0 +1,51 @@
+"""Pytest fixtures and shared utilities for Phyllome OS integration tests."""
+
+import pytest
+from pathlib import Path
+import sys
+
+# Find project root (3 levels up from integration tests)
+PROJECT_ROOT = Path(__file__).resolve().parent.parent.parent
+SCRIPTS_DIR = PROJECT_ROOT / 'scripts'
+sys.path.insert(0, str(SCRIPTS_DIR))
+
+
+@pytest.fixture
+def generator():
+    """Create RecipeGenerator instance."""
+    from generate_recipe import RecipeGenerator
+    
+    ingredients_dir = PROJECT_ROOT / 'ingredients'
+    templates_file = PROJECT_ROOT / 'scripts' / 'recipe_templates.yaml'
+    
+    return RecipeGenerator(ingredients_dir, templates_file)
+
+
+@pytest.fixture
+def project_root():
+    """Return project root directory."""
+    return PROJECT_ROOT
+
+
+@pytest.fixture
+def fragments_dir(project_root):
+    """Return fragments directory."""
+    return project_root / 'fragments'
+
+
+@pytest.fixture
+def recipes_dir(project_root):
+    """Return recipes directory."""
+    return project_root / 'recipes'
+
+
+@pytest.fixture
+def fragments(fragments_dir):
+    """List all .ks fragment files."""
+    return list(fragments_dir.glob('**/*.ks'))
+
+
+@pytest.fixture
+def expected_recipes_dir(project_root):
+    """Return expected recipes directory for golden masters."""
+    return project_root / 'tests' / 'fixtures' / 'expected_recipes'