Improve cert retreival and new newt combined certs

server/lib/clientVersionChecks.ts

@@ -18,3 +18,19 @@ export function canCompress(
         return false;
     }
 }
+
+// Whether this newt client understands `tlsCertId` references into the
+// sync message's `certs` array, instead of requiring each target to carry
+// its own inline `tlsCert`/`tlsKey` PEM data. Bump the version floor here to
+// match whatever release first ships the newt-side support.
+export function supportsCertReferences(
+    clientVersion: string | null | undefined
+): boolean {
+    try {
+        if (!clientVersion) return false;
+        if (!semver.valid(clientVersion)) return false;
+        return semver.gte(clientVersion, "1.16.0");
+    } catch {
+        return false;
+    }
+}