Revert "group sync"

This reverts commit 00c1e52.

Author: tastelikefeet

src/twinkle/sampler/vllm_sampler/vllm_sampler.py

@@ -510,37 +510,27 @@ def receive_weights(
         engine = self._get_or_create_checkpoint_engine()
 
         async def _receive_and_load():
+            # Collect weights with original names — name conversion is done
+            # in the vLLM worker subprocess (TwinkleWorkerExtension).
             weights = {}
-            total_count = 0
-            batch_size = 200
-
             async for name, tensor in engine.receive_weights():
                 weights[name] = tensor.clone()
 
-                if len(weights) >= batch_size:
-                    await self.engine.update_weights(
-                        weights,
-                        peft_config=peft_config,
-                        base_sync_done=base_sync_done,
-                    )
-                    total_count += len(weights)
-                    weights = {}
-
-            if weights:
-                await self.engine.update_weights(
-                    weights,
-                    peft_config=peft_config,
-                    base_sync_done=base_sync_done,
-                )
-                total_count += len(weights)
-
-            if total_count == 0:
+            if not weights:
                 return 0
 
+            await self.engine.update_weights(
+                weights,
+                peft_config=peft_config,
+                base_sync_done=base_sync_done,
+            )
+
+            # After LoRA sync, mark that the synced LoRA is loaded so
+            # sampling automatically uses it.
             if base_sync_done and peft_config:
                 self._ckpt_lora_loaded = True
 
-            return total_count
+            return len(weights)
 
         return self._run_in_loop(_receive_and_load())