fix(tests): auto-init submodules when bats binary is missing (#77)

tests/run-bats.sh

@@ -7,8 +7,12 @@ REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 BATS="$REPO_ROOT/tests/bats/bin/bats"
 
 if [[ ! -x "$BATS" ]]; then
-    echo "Error: bats not found at $BATS" >&2
-    echo "       Run: git submodule update --init --recursive" >&2
+    echo "bats not found at $BATS — initializing submodules..." >&2
+    git -C "$REPO_ROOT" submodule update --init --recursive
+fi
+
+if [[ ! -x "$BATS" ]]; then
+    echo "Error: bats still not found at $BATS after submodule init" >&2
     exit 1
 fi