[Feature][Quant] Reapply auto-detect quantization format and support remote model ID (#7111)

### What this PR does / why we need it?
Reapply the auto-detect quantization format feature (originally in
#6645, reverted in #6873) and extend it to support remote model
identifiers (e.g., `org/model-name`).

Changes:
- Reapply auto-detection of quantization method from model files
(`quant_model_description.json` for ModelSlim, `config.json` for
compressed-tensors)
- Add `get_model_file()` utility to handle file retrieval from both
local paths and remote repos (HuggingFace Hub / ModelScope)
- Update `detect_quantization_method()` to accept remote repo IDs with
optional `revision` parameter
- Update `maybe_update_config()` to work with remote model identifiers
- Add platform-level `auto_detect_quantization` support
- Add unit tests and e2e tests for both local and remote model ID
scenarios

Closes #6836

### Does this PR introduce _any_ user-facing change?

Yes. When `--quantization` is not explicitly specified, vllm-ascend will
now automatically detect the quantization format from the model files
for both local directories and remote model IDs.

- vLLM version: v0.16.0
- vLLM main:
4034c3d32e
---------
Signed-off-by: SlightwindSec <slightwindsec@gmail.com>

tests/ut/test_platform.py

@@ -125,13 +125,14 @@ class TestNPUPlatform(TestBase):
         self.assertIsNone(self.platform.inference_mode())
         mock_inference_mode.assert_called_once()
 
+    @patch("vllm_ascend.quantization.utils.maybe_auto_detect_quantization")
     @patch("vllm_ascend.ascend_config.init_ascend_config")
     @patch("vllm_ascend.utils.update_aclgraph_sizes")
     @patch("vllm_ascend.utils.get_ascend_device_type", return_value=AscendDeviceType.A3)
     @patch("os.environ", {})
     @patch("vllm_ascend.core.recompute_scheduler.RecomputeSchedulerConfig.initialize_from_config")
     def test_check_and_update_config_basic_config_update(
-        self, mock_init_recompute, mock_soc_version, mock_update_acl, mock_init_ascend
+        self, mock_init_recompute, mock_soc_version, mock_update_acl, mock_init_ascend, mock_auto_detect
     ):
         mock_init_ascend.return_value = TestNPUPlatform.mock_vllm_ascend_config()
         vllm_config = TestNPUPlatform.mock_vllm_config()
@@ -155,11 +156,12 @@ class TestNPUPlatform(TestBase):
 
         mock_init_ascend.assert_called_once_with(vllm_config)
 
+    @patch("vllm_ascend.quantization.utils.maybe_auto_detect_quantization")
     @patch("vllm_ascend.utils.get_ascend_device_type", return_value=AscendDeviceType.A3)
     @patch("vllm_ascend.ascend_config.init_ascend_config")
     @patch("vllm_ascend.core.recompute_scheduler.RecomputeSchedulerConfig.initialize_from_config")
     def test_check_and_update_config_no_model_config_warning(
-        self, mock_init_recompute, mock_init_ascend, mock_soc_version
+        self, mock_init_recompute, mock_init_ascend, mock_soc_version, mock_auto_detect
     ):
         mock_init_ascend.return_value = TestNPUPlatform.mock_vllm_ascend_config()
         vllm_config = TestNPUPlatform.mock_vllm_config()
@@ -181,10 +183,11 @@ class TestNPUPlatform(TestBase):
 
         self.assertTrue("Model config is missing" in cm.output[0])
 
+    @patch("vllm_ascend.quantization.utils.maybe_auto_detect_quantization")
     @patch("vllm_ascend.utils.get_ascend_device_type", return_value=AscendDeviceType.A3)
     @patch("vllm_ascend.ascend_config.init_ascend_config")
     @patch("vllm_ascend.core.recompute_scheduler.RecomputeSchedulerConfig.initialize_from_config")
-    def test_check_and_update_config_enforce_eager_mode(self, mock_init_recompute, mock_init_ascend, mock_soc_version):
+    def test_check_and_update_config_enforce_eager_mode(self, mock_init_recompute, mock_init_ascend, mock_soc_version, mock_auto_detect):
         mock_init_ascend.return_value = TestNPUPlatform.mock_vllm_ascend_config()
         vllm_config = TestNPUPlatform.mock_vllm_config()
         vllm_config.model_config.enforce_eager = True
@@ -215,11 +218,12 @@ class TestNPUPlatform(TestBase):
             CUDAGraphMode.NONE,
         )
 
+    @patch("vllm_ascend.quantization.utils.maybe_auto_detect_quantization")
     @patch("vllm_ascend.utils.get_ascend_device_type", return_value=AscendDeviceType.A3)
     @patch("vllm_ascend.ascend_config.init_ascend_config")
     @patch("vllm_ascend.core.recompute_scheduler.RecomputeSchedulerConfig.initialize_from_config")
     def test_check_and_update_config_unsupported_compilation_level(
-        self, mock_init_recompute, mock_init_ascend, mock_soc_version
+        self, mock_init_recompute, mock_init_ascend, mock_soc_version, mock_auto_detect
     ):
         mock_init_ascend.return_value = TestNPUPlatform.mock_vllm_ascend_config()
         vllm_config = TestNPUPlatform.mock_vllm_config()
@@ -253,9 +257,10 @@ class TestNPUPlatform(TestBase):
             )
 
     @pytest.mark.skip("Revert me when vllm support setting cudagraph_mode on oot platform")
+    @patch("vllm_ascend.quantization.utils.maybe_auto_detect_quantization")
     @patch("vllm_ascend.utils.get_ascend_device_type", return_value=AscendDeviceType.A3)
     @patch("vllm_ascend.ascend_config.init_ascend_config")
-    def test_check_and_update_config_unsupported_cudagraph_mode(self, mock_init_ascend, mock_soc_version):
+    def test_check_and_update_config_unsupported_cudagraph_mode(self, mock_init_ascend, mock_soc_version, mock_auto_detect):
         mock_init_ascend.return_value = TestNPUPlatform.mock_vllm_ascend_config()
         vllm_config = TestNPUPlatform.mock_vllm_config()
         vllm_config.model_config.enforce_eager = False
@@ -277,11 +282,12 @@ class TestNPUPlatform(TestBase):
                 CUDAGraphMode.NONE,
             )
 
+    @patch("vllm_ascend.quantization.utils.maybe_auto_detect_quantization")
     @patch("vllm_ascend.utils.get_ascend_device_type", return_value=AscendDeviceType.A3)
     @patch("vllm_ascend.ascend_config.init_ascend_config")
     @patch("vllm_ascend.core.recompute_scheduler.RecomputeSchedulerConfig.initialize_from_config")
     def test_check_and_update_config_cache_config_block_size(
-        self, mock_init_recompute, mock_init_ascend, mock_soc_version
+        self, mock_init_recompute, mock_init_ascend, mock_soc_version, mock_auto_detect
     ):
         mock_init_ascend.return_value = TestNPUPlatform.mock_vllm_ascend_config()
         vllm_config = TestNPUPlatform.mock_vllm_config()
@@ -301,11 +307,12 @@ class TestNPUPlatform(TestBase):
 
         self.assertEqual(vllm_config.cache_config.block_size, 128)
 
+    @patch("vllm_ascend.quantization.utils.maybe_auto_detect_quantization")
     @patch("vllm_ascend.utils.get_ascend_device_type", return_value=AscendDeviceType.A3)
     @patch("vllm_ascend.ascend_config.init_ascend_config")
     @patch("vllm_ascend.core.recompute_scheduler.RecomputeSchedulerConfig.initialize_from_config")
     def test_check_and_update_config_v1_worker_class_selection(
-        self, mock_init_recompute, mock_init_ascend, mock_soc_version
+        self, mock_init_recompute, mock_init_ascend, mock_soc_version, mock_auto_detect
     ):
         mock_init_ascend.return_value = TestNPUPlatform.mock_vllm_ascend_config()
         vllm_config = TestNPUPlatform.mock_vllm_config()
@@ -336,10 +343,11 @@ class TestNPUPlatform(TestBase):
             "vllm_ascend.xlite.xlite_worker.XliteWorker",
         )
 
+    @patch("vllm_ascend.quantization.utils.maybe_auto_detect_quantization")
     @patch("vllm_ascend.ascend_config.init_ascend_config")
     @patch("vllm_ascend.utils.get_ascend_device_type", return_value=AscendDeviceType._310P)
     @patch("vllm_ascend.core.recompute_scheduler.RecomputeSchedulerConfig.initialize_from_config")
-    def test_check_and_update_config_310p_no_custom_ops(self, mock_init_recompute, mock_soc_version, mock_init_ascend):
+    def test_check_and_update_config_310p_no_custom_ops(self, mock_init_recompute, mock_soc_version, mock_init_ascend, mock_auto_detect):
         mock_init_ascend.return_value = TestNPUPlatform.mock_vllm_ascend_config()
         vllm_config = TestNPUPlatform.mock_vllm_config()
         vllm_config.compilation_config.custom_ops = []