ci: Add DevOps quality assurance with pre-commit hooks and GitHub Actions

- Add pre-commit hooks: Ruff lint/format, Bandit security scan, YAML/TOML validation
- Add GitHub Actions CI workflow: lint, security, test, and build jobs
- Configure Ruff and Bandit in pyproject.toml
- Add pytest test suite for build_epub.py (25 tests)
- Fix code issues: exception chaining, httpx timeout, formatting
- Add requirements.txt and requirements-dev.txt

scripts/tests/conftest.py

@@ -0,0 +1,58 @@
+"""Pytest configuration and shared fixtures for EPUB builder tests."""
+
+from __future__ import annotations
+
+import logging
+import sys
+from pathlib import Path
+
+import pytest
+
+# Add parent directory to path for imports
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+from build_epub import BuildState, EPUBConfig, setup_logging
+
+
+@pytest.fixture
+def tmp_project(tmp_path: Path) -> Path:
+    """Create a minimal project structure for testing."""
+    # Create root markdown file
+    readme = tmp_path / "README.md"
+    readme.write_text("# Test Project\n\nThis is a test.")
+
+    # Create a chapter directory
+    chapter_dir = tmp_path / "01-test-chapter"
+    chapter_dir.mkdir()
+    (chapter_dir / "README.md").write_text("# Chapter Overview\n\nOverview content.")
+    (chapter_dir / "section.md").write_text("# Section\n\nSection content.")
+
+    # Create a proper PNG logo using PIL
+    from PIL import Image as PILImage
+
+    logo_path = tmp_path / "claude-howto-logo.png"
+    img = PILImage.new("RGB", (100, 100), color=(26, 26, 46))
+    img.save(logo_path, "PNG")
+
+    return tmp_path
+
+
+@pytest.fixture
+def config(tmp_project: Path) -> EPUBConfig:
+    """Create a test configuration."""
+    return EPUBConfig(
+        root_path=tmp_project,
+        output_path=tmp_project / "test.epub",
+    )
+
+
+@pytest.fixture
+def state() -> BuildState:
+    """Create a fresh build state."""
+    return BuildState()
+
+
+@pytest.fixture
+def logger() -> logging.Logger:
+    """Create a test logger."""
+    return setup_logging(verbose=False)