fix git-crypt unlock detection

Check for .git/git-crypt/keys directory which only exists after
unlock, instead of parsing git-crypt status output which shows
"encrypted:" regardless of lock state.

setup.sh

@@ -39,7 +39,7 @@ fi
 # --- Unlock git-crypt via Bitwarden ---
 
 cd "$REPO_DIR"
-if git-crypt status 2>/dev/null | grep -q '    encrypted:'; then
+if [ ! -d "$REPO_DIR/.git/git-crypt/keys" ]; then
     echo "==> Fetching git-crypt key from Bitwarden..."
     echo "    Log in to Bitwarden when prompted."
     if bw status 2>/dev/null | grep -q '"status":"unauthenticated"'; then