docs: Galaxy alias tags + relay converter (Uns.md, CLAUDE.md)

docs/Uns.md

@@ -95,6 +95,46 @@ Add and edit virtual tags on the equipment page's **Virtual Tags** tab; the
 data type is chosen from the standard OPC UA type list and the Monaco script
 editor is available inline.
 
+### Alias tags
+
+An **alias tag** surfaces a Galaxy attribute under a friendly UNS name without
+requiring a Roslyn script. It is an ordinary equipment `Tag` bound to the
+`GalaxyMxGateway` driver; the Galaxy reference is stored in `TagConfig` as
+`{"FullName":"tag_name.AttributeName"}`. Because the value comes from a direct
+driver subscription — not a script relay — quality and timestamp are native MX,
+and there is no Roslyn overhead.
+
+**Adding an alias:** on the equipment **Tags** tab, click **Add alias (browse
+Galaxy)**. A live Galaxy browse picker opens; navigate to the attribute you
+want. After selecting it, set the tag **Name**, **DataType**, and **AccessLevel**
+(default: read-only; opt in to write-through at your own discretion — writes go
+through the Galaxy driver's security). The button is disabled when the
+equipment's cluster has no `GalaxyMxGateway` driver instance.
+
+In the Tags list, alias tags show an **alias** badge and their Source as
+`galaxy:<tag_name.AttributeName>`. There is no new entity type or schema
+migration — the alias is just a `Tag` row with `DriverType = GalaxyMxGateway`
+and the `FullName` field in its JSON config.
+
+**Relay → alias converter:** if you have existing "relay" virtual tags whose
+scripts are nothing but `return ctx.GetTag("X").Value;`, a converter can
+rewrite them as alias tags automatically:
+
+- **Per-equipment** — a toolbar action on the Tags tab opens a dry-run preview
+  (lists what will be converted and what will be skipped), then a confirm-apply
+  step.
+- **Fleet-wide** — `/uns/convert-relays` (FleetAdmin-gated) runs the same
+  dry-run + apply across all equipment in the fleet.
+
+The converter skips and reports items it cannot safely migrate:
+- virtual tags whose body is not a pure single-value relay
+- virtual tags that are historized
+- equipment whose cluster has no Galaxy gateway
+- relay references containing `{{equip}}` tokens that cannot be resolved
+
+The converter edits the **draft config only** — deploy normally afterward to
+activate the changes.
+
 ## Bulk import
 
 **Import equipment CSV** (toolbar) bulk-creates equipment across many lines