docs: add Packaging Subflows as Custom Nodes page

docs/user/custom-npm-packages.md

@@ -16,6 +16,10 @@ catalogue file. FlowFuse has two solutions for this:
 1. FlowFuse Hosted Nodes - Use the private NPM registry hosted by FlowFuse to store and manage your custom npm packages.
 2. Third-Party NPM Registries - If you already have a private npm registry, you can enable access to these in your Instance's settings.
 
+{% note %}
+To package an existing Node-RED **subflow** as a node from the editor — without hand-authoring an npm package — see [Packaging Subflows](/docs/user/packaging-subflows.md).
+{% endnote %}
+
 ## FlowFuse Hosted Nodes
 
 If you want to create a Node-RED node for private use by Instances in your 

docs/user/packaging-subflows.md

@@ -0,0 +1,54 @@
+---
+navTitle: Packaging Subflows
+meta:
+   description: Package a Node-RED subflow as an installable custom node and publish it to your Team's Custom Nodes library.
+---
+
+# Packaging Subflows as Custom Nodes
+
+FlowFuse can package a Node-RED [subflow](https://nodered.org/docs/user-guide/editor/workspace/subflows) as an installable Node-RED node and publish it to your Team's Custom Nodes library. This lets you maintain a reusable block of logic or UI in one place and pull it into other instances like any other node, instead of copying flows between projects.
+
+{% warning %}
+**Packaging is Hosted Instances only.** You can only *export* a subflow from a **Hosted Instance's** Node-RED editor — not from a Remote Instance (device). Once published, the resulting custom node can be **installed and used on any instance type**, Hosted or Remote.
+{% endwarning %}
+
+## Requirements
+
+- A **Hosted Instance** running the **latest Node-RED version** on **FlowFuse v2.21.0** or later
+- The [Shared Team Library](/docs/user/shared-library.md) feature enabled for the Team
+
+## Packaging a subflow
+
+1. In the Hosted Instance's **Node-RED editor**, build your flow and **convert it to a subflow**.
+2. Open the **Subflow exporter** sidebar and select that subflow.
+3. **Fill out the package details** — the node's **name** and **version** — and hit **Publish**.
+
+![Node-RED editor with the Subflow export sidebar open](./images/subflow-export.png){data-zoomable}
+_The Subflow export sidebar in the Node-RED editor_
+
+FlowFuse builds the subflow into a Node-RED node and publishes it to your Team's Custom Nodes registry, alongside any nodes published as [Custom Node Packages](/docs/user/custom-npm-packages.md).
+
+### Name and version matter
+
+The package details you enter are what the Team installs and updates against, so they aren't throwaway:
+
+- **Name** — becomes the custom node's package name, scoped to your Team (e.g. `@flowfuse-<team id>/<node-name>`; the correct prefix is shown in the FlowFuse application). Keep it stable — republishing under the **same name updates that node** everywhere it's installed, while a **different name creates a separate node**.
+- **Version** — bump it every time you republish. Instances see the new version in the Team Library catalogue and can update to it. This is the low-code **version control** for your custom nodes — no npm or Git to manage yourself.
+
+## Installing the packaged node
+
+The packaged subflow is added to the catalogue generated by your [Shared Team Library](/docs/user/shared-library.md). To use it in any other Node-RED instance in the Team — **Hosted or Remote**:
+
+1. Open **Manage palette** in the Node-RED editor.
+2. Find the packaged node in the catalogue and install it, just like any other node.
+
+![Node-RED Manage palette listing the packaged subflow modules](./images/subflow-catalogue.png){data-zoomable}
+_Packaged subflows appear in Manage palette, ready to install_
+
+Because every instance installs from the same catalogue, you update the subflow in one place and re-publish, rather than editing copies across projects.
+
+## Related
+
+- [Custom Node Packages](/docs/user/custom-npm-packages.md) — publishing custom npm nodes to your Team's registry
+- [Shared Team Library](/docs/user/shared-library.md) — how the Team Library and its catalogue work
+- [Subflows](https://nodered.org/docs/user-guide/editor/workspace/subflows) — the Node-RED concept