Scaffold Python project with pyproject.toml and pytest

Add a src/-layout package (shard_wiki), hatchling build config, pytest
and ruff configuration, and smoke tests proving the import path and test
harness are wired correctly. Update CLAUDE.md with real build/test commands.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

pyproject.toml

@@ -0,0 +1,45 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "shard-wiki"
+version = "0.0.0"
+description = "Git-based Markdown wiki orchestrator and federation layer"
+readme = "README.md"
+requires-python = ">=3.11"
+license = "MIT-0"
+authors = [{ name = "Bernd Worsch", email = "bernd.worsch@gmail.com" }]
+keywords = ["wiki", "markdown", "git", "federation", "orchestration"]
+dependencies = []
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=8.0",
+    "pytest-cov>=5.0",
+    "ruff>=0.6",
+]
+
+[project.urls]
+Homepage = "https://github.com/tegwick/shard-wiki"
+
+[tool.hatch.build.targets.wheel]
+packages = ["src/shard_wiki"]
+
+[tool.pytest.ini_options]
+minversion = "7.0"
+testpaths = ["tests"]
+addopts = "-ra --strict-markers --strict-config"
+pythonpath = ["src"]
+
+[tool.coverage.run]
+branch = true
+source = ["shard_wiki"]
+
+[tool.ruff]
+src = ["src", "tests"]
+target-version = "py311"
+line-length = 100
+
+[tool.ruff.lint]
+select = ["E", "F", "I", "UP", "B", "SIM"]