config: borrowed-record reads follow the config bags (#35908)

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

test/registered/unit/entrypoints/test_v1_loads_aggregate.py

@@ -66,13 +66,24 @@ class _FakeHttpTokenizerManager:
         pp_size=1,
         enable_dp_attention=False,
     ):
+        from sglang.srt.runtime_context import get_context
+
         self.loads = loads
-        self.server_args = SimpleNamespace(
+        # `tp_size` is raw input and still read off the record; the leaves
+        # resolution writes come from the bags.
+        self.server_args = SimpleNamespace(tp_size=tp_size)
+        # The accelerator arithmetic answers "what will this server do", so it
+        # reads the resolved topology out of the bags; publish the shape under test.
+        self._override = get_context().override_server_args(
             tp_size=tp_size,
             dp_size=dp_size,
             pp_size=pp_size,
             enable_dp_attention=enable_dp_attention,
         )
+        self._override.install()
+
+    def restore(self):
+        self._override.restore()
 
     async def get_loads(self, include=None, dp_rank=None):
         results = []
@@ -95,6 +106,7 @@ class TestLoadsResponse(CustomTestCase):
                 )
             ]
         )
+        self.addCleanup(manager.restore)
 
         response = asyncio.run(get_loads(tokenizer_manager=manager))
 
@@ -111,6 +123,7 @@ class TestLoadsAcceleratorField(CustomTestCase):
         """Guards the response contract: the JSON envelope carries an
         accelerator name and the accelerator count for each DP rank."""
         manager = _FakeHttpTokenizerManager([LoadSnapshot(dp_rank=0)], tp_size=16)
+        self.addCleanup(manager.restore)
 
         with mock.patch.object(
             v1_loads, "_accelerator_name", return_value="NVIDIA GB300"
@@ -126,6 +139,7 @@ class TestLoadsAcceleratorField(CustomTestCase):
             dp_size=8,
             enable_dp_attention=True,
         )
+        self.addCleanup(manager.restore)
 
         response = asyncio.run(get_loads(tokenizer_manager=manager))