Wave 3 (#3): tolerate zero previous tags in versionCode check

.gitea/workflows/release.yml

@@ -127,7 +127,7 @@ jobs:
         # so a tag without a bump would strand users on the old build.
         run: |
           CUR=$(grep -oE 'versionCode [0-9]+' android/app/build.gradle | grep -oE '[0-9]+' | head -1)
-          PREV_TAG=$(git tag --sort=-v:refname | grep -E '^v[0-9]+\.[0-9]+\.[0-9]+$' | head -2 | tail -1)
+          PREV_TAG=$(git tag --sort=-v:refname 2>/dev/null | grep -E '^v[0-9]+\.[0-9]+\.[0-9]+$' | head -2 | tail -1 || true)
           if [ -n "$PREV_TAG" ]; then
             PREV=$(git show "$PREV_TAG:android/app/build.gradle" | grep -oE 'versionCode [0-9]+' | grep -oE '[0-9]+' | head -1)
             echo "versionCode: $PREV ($PREV_TAG) -> $CUR (${GITHUB_REF_NAME})"