feat: add StorageAdapter abstraction and InMemoryAdapter with full test suite

- Introduce StorageAdapter protocol and InMemoryAdapter (thread-safe, in-memory)
  in engine/adapter.py to decouple storage from sync logic
- Refactor SyncEngine to accept a StorageAdapter, replacing the previous
  stub that returned an empty list
- Wire server to use SyncEngine + InMemoryAdapter, removing hardcoded
  SYNC_OPERATIONS fixtures
- Add tests for engine, adapter, generator, and types (tests/)
- Add pre-commit config (.pre-commit-config.yaml) with linting/formatting hooks
- Update pyproject.toml and uv.lock with new dev dependencies
- Clean up type annotations and CLI help strings across generator, server, and utils

pyproject.toml

@@ -25,3 +25,74 @@ build-backend = "hatchling.build"
 
 [tool.hatch.build.targets.wheel]
 packages = ["src/generator"]
+
+[tool.pytest.ini_options]
+pythonpath = ["src"]
+testpaths = ["tests"]
+
+# ---------------------------------------------------------------------------
+# Black
+# ---------------------------------------------------------------------------
+
+[tool.black]
+line-length = 88
+target-version = ["py312"]
+
+# ---------------------------------------------------------------------------
+# Ruff
+# ---------------------------------------------------------------------------
+
+[tool.ruff]
+line-length = 88
+target-version = "py312"
+src = ["src"]
+
+[tool.ruff.lint]
+select = [
+    "E",   # pycodestyle errors
+    "W",   # pycodestyle warnings
+    "F",   # pyflakes
+    "I",   # isort
+    "B",   # flake8-bugbear
+    "UP",  # pyupgrade
+    "C4",  # flake8-comprehensions
+    "SIM", # flake8-simplify
+    "ANN", # flake8-annotations
+    "RUF", # ruff-specific rules
+]
+ignore = [
+    "ANN401", # allow Any in some places
+]
+
+[tool.ruff.lint.isort]
+known-first-party = ["engine", "server", "client", "generator", "utils"]
+
+[tool.ruff.lint.per-file-ignores]
+"tests/**" = ["ANN"] # don't require annotations in tests
+
+# ---------------------------------------------------------------------------
+# Mypy
+# ---------------------------------------------------------------------------
+
+[tool.mypy]
+python_version = "3.12"
+mypy_path = "src"
+strict = true
+# Pydantic plugin for correct model field inference
+plugins = ["pydantic.mypy"]
+
+[tool.pydantic-mypy]
+init_forbid_extra = true
+warn_required_dynamic_aliases = true
+
+[dependency-groups]
+dev = [
+    "black>=26.5.1",
+    "mypy>=2.3.1",
+    "pre-commit>=4.6.2",
+    "rope>=1.14.0",
+    "ruff>=0.16.4",
+]
+test = [
+    "pytest>=9.1.1",
+]