fix: add missing git-branch parameter to compile-and-train template

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

infra/k8s/argo/compile-and-train-template.yaml

@@ -39,6 +39,8 @@ spec:
       # ── Compile ──
       - name: commit-sha
         value: HEAD
+      - name: git-branch
+        value: main
       - name: cuda-compute-cap
         value: "90"
       # ── Training ──