fix(ci): install torch from cu130 index in venv step

train.py imports torch but the venv step only installed requirements.txt,
which deliberately excludes torch (must come from the cu130 wheel index for
koala's Blackwell sm_120, per the requirements.txt header). Baseline run died
with ModuleNotFoundError: No module named 'torch'. Add the documented install.

.gitea/workflows/autoresearch.yml

@@ -42,6 +42,9 @@ jobs:
       - name: Set up Python venv
         run: |
           [ -d .venv ] || python3 -m venv .venv
+          # torch must come from the cu130 wheel index (koala Blackwell sm_120);
+          # requirements.txt deliberately excludes it. Install it first.
+          .venv/bin/pip install -q torch --index-url https://download.pytorch.org/whl/cu130
           .venv/bin/pip install -q -r requirements.txt
 
       - name: Scaffold run dir