[Core] Composable parallel: Phase 1 strategy overlay (TP/DP/stage-replica) (RFC #4084) (#4281)

Signed-off-by: Kushan A. <kahmadian@nvidia.com>
Signed-off-by: kushanam <kushanam@users.noreply.github.com>
Signed-off-by: Kushan A <kahmadian@nvidia.com>
Signed-off-by: kahmadian <kahmadian@users.noreply.github.com>
Co-authored-by: kushanam <kushanam@users.noreply.github.com>
Co-authored-by: kahmadian <kahmadian@users.noreply.github.com>

tests/entrypoints/test_utils.py

@@ -318,7 +318,7 @@ class TestLoadAndResolveStageConfigs:
     def test_load_and_resolve_with_kwargs(self):
         """Ensure that dtype survives default stage creation."""
         kwargs = {"dtype": torch.float32}
-        config_path, stage_configs = load_and_resolve_stage_configs(
+        config_path, stage_configs, _ = load_and_resolve_stage_configs(
             model="black-forest-labs/FLUX.2-klein-4B",
             stage_configs_path=None,
             kwargs=kwargs,
@@ -349,10 +349,10 @@ class TestLoadAndResolveStageConfigs:
         ]
         load_stage_configs = mocker.patch(
             "vllm_omni.entrypoints.utils.load_stage_configs_from_model",
-            return_value=returned_stage_configs,
+            return_value=(returned_stage_configs, None),
         )
 
-        config_path, stage_configs = load_and_resolve_stage_configs(
+        config_path, stage_configs, _ = load_and_resolve_stage_configs(
             model="dummy-model",
             stage_configs_path=str(deploy_path),
             kwargs={},
@@ -363,6 +363,7 @@ class TestLoadAndResolveStageConfigs:
             base_engine_args={},
             deploy_config_path=str(deploy_path),
             stage_overrides=None,
+            strategy_config_path=None,
         )
         assert config_path == str(deploy_path)
         assert len(stage_configs) == 2