Lock the steer extra and pin the Modal image builder

Co-Authored-By: Claude <288921227+claudypoo@users.noreply.github.com>

.gitignore

@@ -16,3 +16,4 @@ dist/
 build/
 results/
 logs_*.log
+outputs/

justfile

@@ -1,3 +1,6 @@
+# uv_sync images need a 2025+ builder; the workspace default is still 2024.10
+export MODAL_IMAGE_BUILDER_VERSION := "2025.06"
+
 # smoke test: 5-item forced-choice eval on existing classic data
 smoke:
     uv run python scripts/09_forced_choice.py --model Qwen/Qwen3-0.6B --limit 5 2>&1 | tee logs_smoke.log