Spine fix: planner installs recipe deps (stage-2 launch scar)

src/pipeline/contracts.py

@@ -122,6 +122,14 @@ class RecipeSpec(_Strict):
     stages: list[StageSpec] = Field(min_length=1)
     gates: GateSpec
     negative_results: list[str] = Field(default_factory=list)
+    deps: list[str] = Field(
+        default_factory=lambda: [
+            "torch==2.5.1",
+            "transformers==4.46.3",
+            "accelerate>=1.1.0",
+            "sentencepiece",
+        ]
+    )
     channel: Literal["gh-releases"] = "gh-releases"
 
     @field_validator("corpora")

src/pipeline/planner.py

@@ -36,6 +36,11 @@ def plan_stage(
     prefix = stage.env_prefix
     env = {f"{prefix}_{k.upper()}": str(v) for k, v in stage.params.items()}
     env[f"{prefix}_RUN"] = run
+    # legacy scripts need their wheels; the recipe declares them and the
+    # planner installs before exec (the bare-python launch, 6ad494b9,
+    # died on `No module named torch` — this is that scar, encoded)
+    bootstrap = "pip install -q " + " ".join(recipe.deps)
+    command = ["bash", "-c", f"{bootstrap} && python {CKPT_MOUNT}/{run}/{script}"]
     volumes = [Volume(CKPT_BUCKET, CKPT_MOUNT, "rw")]
     seen: set[str] = set()
     idx = 0
@@ -58,7 +63,7 @@ def plan_stage(
             idx += 1
     return JobSpec(
         name=run,
-        command=["python", f"{CKPT_MOUNT}/{run}/{script}"],
+        command=command,
         flavor=flavor,
         timeout_h=timeout_h,
         volumes=volumes,

tests/test_pipeline_plan_gate.py

@@ -26,8 +26,8 @@ def test_plan_sft_stage_builds_lawful_job() -> None:
     sft = recipe.stages[0]
     spec = plan_stage(recipe, sft, run="run-066-urd-diac-base")
     assert spec.name == "run-066-urd-diac-base"
-    assert spec.command[0] == "python"
-    assert spec.command[1].endswith("train_urd_diac_base_hf.py")
+    assert spec.command[0] == "bash" and spec.command[1] == "-c"
+    assert spec.command[2].endswith("train_urd_diac_base_hf.py")
     mounts = [v.mount for v in spec.volumes]
     assert "/ckpt" in mounts and "/data-dia" in mounts
     ro = {v.mount: v.mode for v in spec.volumes}
@@ -120,3 +120,15 @@ def test_gate_results_files_end_to_end(tmp_path: Path) -> None:
     )
     by_name = {g.name: g.passed for g in results}
     assert by_name == {"quality": True, "parity": True, "license": False}
+
+
+def test_plan_wraps_legacy_deps() -> None:
+    """The first dogfooded launch (stage-2, 6ad494b9) died on a bare
+    python command — the spine must install the recipe's deps."""
+    recipe = load_recipe(RECIPES / "ara-diac.yaml")
+    spec = plan_stage(recipe, recipe.stages[1], run="run-x")
+    assert spec.command[0] == "bash" and spec.command[1] == "-c"
+    cmd = spec.command[2]
+    assert cmd.startswith("pip install -q ")
+    assert "torch==" in cmd and "transformers==" in cmd
+    assert cmd.endswith("python /ckpt/run-x/continue_oracle_train_hf.py")