docs: add dupontbertrand:cluster to community packages

- Add documentation page for dupontbertrand:cluster, a Meteor 3
  compatible fork of meteorhacks:cluster
- Add entry to community packages index under new Scaling / Clustering
  category
- Add sidebar navigation entry

v3-docs/docs/.vitepress/config.mts

@@ -461,6 +461,10 @@ export default defineConfig({
                 text: "jam:offline",
                 link: "/community-packages/offline",
               },
+              {
+                text: "dupontbertrand:cluster",
+                link: "/community-packages/cluster",
+              },
             ],
             collapsed: true,
           },

v3-docs/docs/community-packages/cluster.md

@@ -0,0 +1,152 @@
+# Cluster
+
+- `Who maintains the package` – [Bertrand Dupont](https://github.com/dupontbertrand)
+
+[[toc]]
+
+## What Is It?
+
+A Meteor 3 compatible fork of [`meteorhacks:cluster`](https://github.com/meteorhacks/cluster), providing multi-core support, load balancing, and service discovery for Meteor apps.
+
+The original package was abandoned around 2016. This fork ports it to Meteor 3 with async/await, modern dependencies, and updated MongoDB driver — while preserving the same public API.
+
+::: warning
+This is a **compatibility / migration bridge**, not a new recommended scaling architecture. If you only need multi-core CPU utilization, an external process manager like [PM2](https://pm2.keymetrics.io/) is simpler. This package is for apps that relied on `meteorhacks:cluster` features like service discovery, DDP-aware proxying, or `Cluster.discoverConnection()`.
+:::
+
+## How to Download It?
+
+```bash
+meteor add dupontbertrand:cluster
+```
+
+## How to Use It?
+
+### Multi-Core (Simplest Use Case)
+
+Just set the `CLUSTER_WORKERS_COUNT` environment variable:
+
+```bash
+# Use all available CPU cores
+CLUSTER_WORKERS_COUNT=auto meteor run
+
+# Or specify a number
+CLUSTER_WORKERS_COUNT=4 meteor run
+```
+
+The package forks child processes automatically. No code changes needed.
+
+### Service Discovery + Load Balancing
+
+For multi-instance deployments with automatic service registration and DDP-aware load balancing:
+
+```bash
+export CLUSTER_DISCOVERY_URL="mongodb://your-mongo-host/cluster"
+export CLUSTER_SERVICE="web"
+export CLUSTER_WORKERS_COUNT=2
+```
+
+Instances register themselves in MongoDB and discover each other automatically. No need to reconfigure a load balancer when adding or removing instances.
+
+### Microservices
+
+Connect to other services in the cluster by name:
+
+```js
+// Server
+const serviceConnection = Cluster.discoverConnection('payments');
+
+// Call methods on the remote service
+const result = await serviceConnection.callAsync('processPayment', data);
+```
+
+## API
+
+### `Cluster.connect(discoveryUrl, [options])`
+
+Connect to a discovery backend (currently MongoDB).
+
+```js
+Cluster.connect('mongodb://host/db');
+```
+
+Usually configured via the `CLUSTER_DISCOVERY_URL` environment variable instead of calling directly.
+
+### `Cluster.register(serviceName, [options])`
+
+Register this instance as a named service.
+
+```js
+Cluster.register('web');
+```
+
+Options:
+- `endpoint` — the URL other instances use to reach this one (defaults to `ROOT_URL`)
+- `balancer` — URL of the balancer (defaults to `CLUSTER_BALANCER_URL`)
+- `uiService` — the service that serves the UI (defaults to the registered service name)
+
+Usually configured via the `CLUSTER_SERVICE` environment variable.
+
+### `Cluster.discoverConnection(serviceName, [ddpOptions])`
+
+Get a DDP connection to a named service. The connection automatically tracks healthy instances via the discovery backend.
+
+```js
+const conn = Cluster.discoverConnection('analytics');
+const data = await conn.callAsync('getReport', params);
+```
+
+### `Cluster.allowPublicAccess(serviceList)`
+
+Allow public (non-authenticated) access to specific services.
+
+```js
+Cluster.allowPublicAccess(['web', 'api']);
+```
+
+Usually configured via the `CLUSTER_PUBLIC_SERVICES` environment variable (comma-separated).
+
+## Environment Variables
+
+| Variable | Description | Default |
+| -------- | ----------- | ------- |
+| `CLUSTER_WORKERS_COUNT` | Number of worker processes (`auto` = all cores) | 1 (no clustering) |
+| `CLUSTER_DISCOVERY_URL` | MongoDB URL for service discovery | — |
+| `CLUSTER_SERVICE` | Name to register this instance as | — |
+| `CLUSTER_ENDPOINT_URL` | URL for other instances to reach this one | `ROOT_URL` |
+| `CLUSTER_BALANCER_URL` | URL of the load balancer | — |
+| `CLUSTER_PUBLIC_SERVICES` | Comma-separated list of public services | — |
+| `CLUSTER_UI_SERVICE` | Service that serves the UI | same as `CLUSTER_SERVICE` |
+
+## What Changed From meteorhacks:cluster
+
+This fork preserves the original API. Under the hood:
+
+- MongoDB discovery backend rewritten in **async/await** (was Fibers/wrapAsync)
+- MongoDB driver updated from 1.4.x to **6.12.0**
+- `underscore` replaced with native ES2015+
+- npm dependencies updated (`cookies`, `http-proxy`, `portscanner`)
+- Fixed `Buffer()` deprecation and a pre-existing IPC listener bug
+- Balancer made transport-aware for compatibility with pluggable transports ([#14231](https://github.com/meteor/meteor/pull/14231))
+- Test suite adapted for Meteor 3
+
+Full changelog: [METEOR3-PORT.md](https://github.com/dupontbertrand/cluster/blob/master/METEOR3-PORT.md)
+
+## Known Limitations
+
+- The balancer uses `OverShadowServerEvent` to intercept HTTP/WS traffic at the `httpServer` level. This is invasive and could break if Meteor changes its listener initialization order.
+- No Windows testing yet.
+- The worker pool uses `child_process.fork` with per-worker ports (not `node:cluster`).
+
+## Compatibility
+
+- Meteor 3.4+
+- Node 22
+- Tested on Linux
+
+## Sources
+
+- **Atmosphere:** [dupontbertrand:cluster](https://atmospherejs.com/dupontbertrand/cluster)
+- **GitHub:** [dupontbertrand/cluster](https://github.com/dupontbertrand/cluster)
+- **Original package:** [meteorhacks/cluster](https://github.com/meteorhacks/cluster)
+- **Forum Discussion:** [Memory usage and sessions quadruple after upgrading to Meteor 3](https://forums.meteor.com/t/memory-usage-and-sessions-quadruple-after-upgrading-to-meteor-3/64496)

v3-docs/docs/community-packages/index.md

@@ -36,6 +36,10 @@ Please bear in mind if you are adding a package to this list, try providing as m
 - [`jam:soft-delete`](./soft-delete.md), An easy way to add soft deletes to your Meteor app
 - [`jam:archive`](./archive.md),
 
+#### Scaling / Clustering
+
+- [`dupontbertrand:cluster`](./cluster.md), Meteor 3 fork of meteorhacks:cluster — multi-core, load balancing, service discovery
+
 #### Utilities
 
 - [`jam:offline`](./offline.md), An easy way to give your Meteor app offline capabilities and make it feel instant