feat: add integration smoke tests

CLI-level smoke tests using --yaml output against real Twitter API.
Default skipped via @pytest.mark.smoke marker + pyproject.toml addopts.
Run locally with: uv run pytest -m smoke -v

pyproject.toml

@@ -33,6 +33,8 @@ dependencies = [
 dev = [
     "pytest>=8.0",
     "ruff>=0.8",
+    "mypy>=1.14,<1.15",
+    "types-PyYAML>=6.0.12",
 ]
 
 [project.urls]
@@ -46,9 +48,20 @@ twitter = "twitter_cli.cli:cli"
 [tool.pytest.ini_options]
 testpaths = ["tests"]
 python_files = ["test_*.py"]
+addopts = "-m 'not smoke'"
+markers = [
+    "smoke: real-API integration tests (run with: pytest -m smoke)",
+]
 
 [tool.ruff]
 line-length = 100
 
+[tool.mypy]
+python_version = "3.8"
+ignore_missing_imports = true
+check_untyped_defs = true
+warn_unused_ignores = true
+no_implicit_optional = true
+
 [tool.hatch.build.targets.wheel]
 packages = ["twitter_cli"]