Add ModelScope dataset download support

SKILL.md

@@ -1,6 +1,6 @@
 # TI Coding Agent Probe Skill
 
-Use this skill when the user wants to run or modify the TI coding-agent SFT probe experiments based on the Hugging Face dataset `ti_coding_agent_training_probe_20260624`.
+Use this skill when the user wants to run or modify the TI coding-agent SFT probe experiments based on the ModelScope dataset `eigentom/ti_coding_agent_training_probe_20260624`. Hugging Face remains available as a fallback backend.
 
 ## Repository Contract
 
@@ -25,9 +25,24 @@ git submodule update --init --recursive
 ./scripts/setup_env.sh
 ```
 
-Download the training probe dataset:
+Download the training/eval probe dataset from ModelScope:
 
 ```bash
+export MODELSCOPE_API_TOKEN=<modelscope-api-key>
+./scripts/download_dataset.py
+```
+
+The downloader writes:
+
+- `data/raw/training_probe/{train,validation}.jsonl.gz`
+- `data/raw/training_probe/{train,validation}.parquet`
+- `data/processed/training_probe/{train,validation}.jsonl`
+- `data/processed/training_probe/{train,validation}.parquet`
+
+Use Hugging Face fallback only when requested:
+
+```bash
+export DATASET_BACKEND=huggingface
 export HF_ENDPOINT=https://hf-mirror.com
 export HF_DATASET_REPO_ID=<owner>/ti_coding_agent_training_probe_20260624
 ./scripts/download_dataset.py