feat(m1): scaffold tsmm package (T1.1)

- pyproject.toml (src-layout, deps per plan)
- src/tsmm/{data,model,train,eval} skeletons
- tests/test_smoke.py (RED->GREEN: importable + subpackages)
- configs/, scripts/, data/, checkpoints/ + .gitignore
- project venv (.venv) for reproducible env (M1 deps only; CUDA torch @ M2)

Verifications: import tsmm OK; pytest tests/ 3 passed.

pyproject.toml

@@ -0,0 +1,35 @@
+[build-system]
+requires = ["setuptools>=68", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "tsmm"
+version = "0.0.1"
+description = "Time-series as a modality: multimodal TS-question-answering model (experimental, single-GPU)"
+readme = "README.md"
+requires-python = ">=3.10"
+license = { text = "MIT" }
+authors = [{ name = "tsmm contributors" }]
+dependencies = [
+    "torch",
+    "transformers",
+    "peft",
+    "accelerate",
+    "datasets",
+    "numpy",
+    "tqdm",
+    "pyyaml",
+    "pytest",
+]
+
+[project.optional-dependencies]
+# Heavy GPU deps installed on-demand at M2 (CUDA torch build, etc.)
+dev = ["pytest", "pytest-cov"]
+
+[tool.setuptools.packages.find]
+where = ["src"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+pythonpath = ["src"]
+addopts = "-q"