Fix base model: point adapter at Qwen/Qwen3.5-2B-Base (the true training base; -Base, not the finetune)

adapter_config.json

@@ -5,7 +5,7 @@
   },
   "arrow_config": null,
   "auto_mapping": null,
-  "base_model_name_or_path": "Qwen/Qwen3.5-2B",
+  "base_model_name_or_path": "Qwen/Qwen3.5-2B-Base",
   "bias": "none",
   "corda_config": null,
   "ensure_weight_tying": false,
@@ -58,4 +58,4 @@
   "use_dora": false,
   "use_qalora": false,
   "use_rslora": false
-}
+}