chore: operator env example and deployment script touch-ups

Made-with: Cursor

scripts/lib/deployment/dotenv.sh

@@ -29,6 +29,16 @@ load_deployment_env() {
     source "$dotenv"
     set +a
   fi
+  local secure_secrets_file="${SECURE_SECRETS_FILE:-$HOME/.secure-secrets/private-keys.env}"
+  if [[ -f "$secure_secrets_file" ]]; then
+    set -a
+    # shellcheck disable=SC1090
+    source "$secure_secrets_file"
+    set +a
+  fi
+  if [[ -z "${PRIVATE_KEY:-}" && -n "${DEPLOYER_PRIVATE_KEY:-}" ]]; then
+    export PRIVATE_KEY="$DEPLOYER_PRIVATE_KEY"
+  fi
 }
 
 # Require vars for mainnet LP funding (G4). Fails with message if missing.