Initial release: E1 genus probe package moved out of the E01 workflow

- src/custom_models torch modules, store, training, metrics, runner and CLI
  (package-relative imports for pip installability)
- test suite (49 tests) + conftest with fast synthetic-store fixtures
- uv-managed dev env (pyproject + CPU torch index), hatchling build
- README: uv for the package, pip install into conda envs for the workflow

tests/conftest.py

@@ -0,0 +1,50 @@
+"""Shared fixtures: fast synthetic stores (no pod5 needed) and determinism."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+import pytest
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "src"))
+
+from custom_models.seed import seed_everything
+from custom_models.store import synthetic_store
+
+
+@pytest.fixture(autouse=True)
+def _seed_every_test() -> None:
+    """Seed all RNGs before each test (the GATE ZERO §2.3 contract)."""
+    seed_everything(0)
+
+
+@pytest.fixture(scope="session")
+def fast_store(tmp_path_factory: pytest.TempPathFactory) -> Path:
+    """A small 6-genus duty-cycle store for split/config tests."""
+    out = tmp_path_factory.mktemp("store") / "main"
+    synthetic_store(
+        out_dir=out,
+        n_genera=6,
+        reads_per_genus=12,
+        window_samples=1200,
+        shard_windows=8,
+        seed=0,
+    )
+    return out
+
+
+@pytest.fixture(scope="session")
+def trap_store(tmp_path_factory: pytest.TempPathFactory) -> Path:
+    """A small eval-only impostor store (and test-split source)."""
+    out = tmp_path_factory.mktemp("store") / "trap"
+    synthetic_store(
+        out_dir=out,
+        n_genera=2,
+        reads_per_genus=6,
+        window_samples=1200,
+        shard_windows=8,
+        seed=1,
+        genus_prefix="trap_",
+    )
+    return out