feat(enterprise): add auth TLS and recovery hardening

readme.md

@@ -248,6 +248,62 @@ const server = new SmartdbServer({
   persistPath: './data/snapshot.json',
   persistIntervalMs: 30000, // Save every 30s
 });
+
+// TLS transport for TCP mode
+const tlsServer = new SmartdbServer({
+  port: 27017,
+  tls: {
+    enabled: true,
+    certPath: './certs/server.pem',
+    keyPath: './certs/server.key',
+    // caPath: './certs/client-ca.pem',
+    // requireClientCert: true, // Enables mTLS client certificate checks
+  },
+});
+
+// SCRAM-SHA-256 authentication
+const secureServer = new SmartdbServer({
+  port: 27017,
+  auth: {
+    enabled: true,
+    usersPath: './data/smartdb-users.json', // Optional: persists derived SCRAM credentials
+    users: [
+      {
+        username: 'root',
+        password: 'change-me',
+        database: 'admin',
+        roles: ['root'],
+      },
+    ],
+  },
+});
+```
+
+When `auth.enabled` is true, protected commands require successful SCRAM-SHA-256 authentication through the official MongoDB driver:
+
+```typescript
+const client = new MongoClient('mongodb://root:change-me@127.0.0.1:27017/admin?authSource=admin', {
+  directConnection: true,
+});
+await client.connect();
+```
+
+TLS is available for TCP listeners. `getConnectionUri()` includes `?tls=true` when TLS is enabled; pass the trusted CA to the MongoDB driver with `tlsCAFile`, `ca`, or `secureContext`.
+
+Authentication verifies SCRAM credentials, denies unauthenticated commands, and enforces command-level built-in roles for supported operations.
+
+Supported built-in role names are `root`, `read`, `readWrite`, `dbAdmin`, `userAdmin`, `clusterMonitor`, plus `readAnyDatabase`, `readWriteAnyDatabase`, `dbAdminAnyDatabase`, and `userAdminAnyDatabase`. When `usersPath` is set, SmartDB persists SCRAM credential material atomically and does not store plaintext passwords.
+
+Basic user management commands are available for authenticated users with `root` or `userAdmin` privileges:
+
+```typescript
+await client.db('admin').command({
+  createUser: 'reader',
+  pwd: 'readpass',
+  roles: [{ role: 'read', db: 'myapp' }],
+});
+
+await client.db('admin').command({ usersInfo: 'reader' });
 ```
 
 #### Methods & Properties