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

pyproject.toml

@@ -0,0 +1,100 @@
+[project]
+name = "claude-howto"
+version = "1.0.0"
+description = "Claude Code How-To Guide with EPUB builder"
+readme = "README.md"
+license = {text = "MIT"}
+requires-python = ">=3.10"
+dependencies = [
+    "ebooklib",
+    "markdown",
+    "beautifulsoup4",
+    "httpx",
+    "pillow",
+    "tenacity",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=7.0",
+    "pytest-asyncio>=0.21",
+]
+
+[tool.pytest.ini_options]
+testpaths = ["scripts/tests"]
+asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
+python_files = ["test_*.py"]
+python_functions = ["test_*"]
+addopts = "-v"
+
+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"
+
+# =============================================================================
+# Ruff Configuration
+# =============================================================================
+[tool.ruff]
+target-version = "py310"
+line-length = 88
+include = ["scripts/**/*.py"]
+exclude = [
+    ".git",
+    ".venv",
+    "__pycache__",
+    ".pytest_cache",
+    "*.egg-info",
+]
+
+[tool.ruff.lint]
+select = [
+    "E",      # pycodestyle errors
+    "W",      # pycodestyle warnings
+    "F",      # Pyflakes
+    "I",      # isort (import sorting)
+    "B",      # flake8-bugbear
+    "C4",     # flake8-comprehensions
+    "UP",     # pyupgrade
+    "SIM",    # flake8-simplify
+    "TCH",    # flake8-type-checking
+    "RUF",    # Ruff-specific rules
+    "PTH",    # flake8-use-pathlib
+    "PL",     # Pylint
+    "PERF",   # Perflint
+]
+ignore = [
+    "E501",     # Line too long (handled by formatter)
+    "PLR0913",  # Too many arguments
+    "PLR2004",  # Magic value comparison
+    "PLR0915",  # Too many statements
+    "PERF203",  # try-except in loop (acceptable for error handling)
+    "PERF403",  # dict comprehension (readability preference)
+    "TC003",    # Type-checking imports (not critical)
+    "PLC0415",  # Import not at top level (acceptable for lazy imports)
+    "RUF005",   # Collection concatenation (readability preference)
+]
+fixable = ["ALL"]
+unfixable = []
+
+[tool.ruff.lint.isort]
+known-first-party = ["build_epub"]
+force-single-line = false
+combine-as-imports = true
+
+[tool.ruff.lint.per-file-ignores]
+"scripts/tests/*.py" = ["S101", "PLR2004"]
+
+[tool.ruff.format]
+quote-style = "double"
+indent-style = "space"
+skip-magic-trailing-comma = false
+docstring-code-format = true
+
+# =============================================================================
+# Bandit Configuration
+# =============================================================================
+[tool.bandit]
+targets = ["scripts"]
+exclude_dirs = ["scripts/tests", ".venv", "__pycache__"]
+skips = ["B101", "B113"]  # B113: httpx timeout false positive (timeout is set)