Add argon2 polyfill and unified preview/API startup for admin login.

Node < 24 lacks crypto.argon2Sync; wire @node-rs/argon2 fallback and start Admin API alongside vite preview in local and remote deploy flows.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/argon2-polyfill.mjs

@@ -0,0 +1,23 @@
+import crypto from 'node:crypto';
+import { Algorithm, hashRawSync } from '@node-rs/argon2';
+
+/** Node < 24 无 crypto.argon2Sync，Memind user-auth 登录会崩溃。 */
+export function ensureArgon2Sync() {
+  if (typeof crypto.argon2Sync === 'function') return;
+
+  crypto.argon2Sync = (algorithm, options = {}) => {
+    if (algorithm !== 'argon2id') {
+      throw new Error(`unsupported argon2 algorithm: ${algorithm}`);
+    }
+    const message = options.message ?? '';
+    const nonce = options.nonce ?? Buffer.alloc(0);
+    return hashRawSync(String(message), {
+      algorithm: Algorithm.Argon2id,
+      salt: nonce,
+      parallelism: options.parallelism ?? 1,
+      outputLen: options.tagLength ?? 32,
+      memoryCost: options.memory ?? 65536,
+      timeCost: options.passes ?? 3,
+    });
+  };
+}