[Model] Reduce MOSS-TTS Local intermediate output overhead

Keep internal talker control outputs FINAL_ONLY while codec audio remains incremental. Reapply pipeline sampling constraints after default streaming coercion, log routine coercions at debug level, and cover explicit/default parameters with regression tests. Document matched high-concurrency statistics settings.

Signed-off-by: Sy03 <1370724210@qq.com>

tests/model_executor/models/moss_tts/test_local_output_policy.py

@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM-Omni project
+
+import pytest
+from vllm import SamplingParams
+from vllm.sampling_params import RequestOutputKind
+
+from vllm_omni.entrypoints.omni_base import OmniBase
+from vllm_omni.entrypoints.utils import coerce_param_message_types
+from vllm_omni.model_executor.models.moss_tts.pipeline import MOSS_TTS_LOCAL_PIPELINE
+
+pytestmark = [pytest.mark.core_model, pytest.mark.cpu]
+
+
+@pytest.mark.parametrize("use_defaults", [False, True])
+def test_local_talker_control_outputs_preserve_codec_streaming(mocker, use_defaults):
+    base = object.__new__(OmniBase)
+    base.engine = mocker.Mock(num_stages=2)
+    base.sampling_constraints_list = [dict(stage.sampling_constraints) for stage in MOSS_TTS_LOCAL_PIPELINE.stages]
+    base.default_sampling_params_list = [
+        base._apply_sampling_constraints(SamplingParams(max_tokens=8, seed=11), constraints)
+        for constraints in base.sampling_constraints_list
+    ]
+    caller = coerce_param_message_types(
+        [SamplingParams(max_tokens=8, seed=11), SamplingParams(max_tokens=8, seed=11)], True
+    )
+    result = base.resolve_sampling_params_list(None if use_defaults else caller, allow_delta_coercion=True)
+
+    assert result[0].output_kind == RequestOutputKind.FINAL_ONLY
+    assert result[0].detokenize is False
+    assert result[0].max_tokens == 8
+    assert result[0].seed == 11
+    assert result[1].output_kind == RequestOutputKind.DELTA
+    assert caller[0].output_kind == RequestOutputKind.DELTA
+    assert base.default_sampling_params_list[0].output_kind == RequestOutputKind.FINAL_ONLY
+    assert MOSS_TTS_LOCAL_PIPELINE.stages[0].final_output is False
+    assert MOSS_TTS_LOCAL_PIPELINE.stages[1].final_output_type == "audio"