fix(adminui): preserve edited alarm fields on Galaxy address re-pick

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagModal.razor

@@ -336,14 +336,12 @@
     private void OnGalaxyAddressPicked(string address)
     {
         _galaxyAddress = address;
-        // A fresh {FullName} blob would drop any tag-level historize the operator already set on this
-        // edit; re-merge it so re-picking a Galaxy address never silently clears "Historize this tag".
-        var config = TagHistorizeConfig.Set(
-            JsonSerializer.Serialize(new { FullName = address }),
-            _historizeState.IsHistorized,
-            _historizeState.HistorianTagname);
-        // Re-merge any array intent for the same reason — a fresh {FullName} blob would otherwise drop it.
-        config = TagArrayConfig.Set(config, _arrayState.IsArray, _arrayState.ArrayLength);
+        // Re-picking a Galaxy address owns ONLY the address-derived FullName key — apply it over the EXISTING
+        // TagConfig so every other user-edited field survives verbatim. This preserves a hand-authored `alarm`
+        // object (FB-4: a re-pick must never clobber edited alarm fields) as well as the root history/array
+        // intent and any driver/unknown keys. TagConfigJson.SetFullName uses the same preserve-unknown idiom
+        // as the historize/array merge seams.
+        var config = TagConfigJson.SetFullName(_form.TagConfig, address);
         _form.TagConfig = _galaxyPickedIsAlarm
             ? NativeAlarmModel.SeedDefaultAlarm(config)
             : config;

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigJson.cs

@@ -43,4 +43,19 @@ public static class TagConfigJson
         if (value is null) { o.Remove(name); return; }
         o[name] = JsonValue.Create(value is Enum e ? e.ToString() : value);
     }
+
+    /// <summary>
+    /// Merges a freshly-picked Galaxy reference (<c>tag_name.AttributeName</c>) into <paramref name="json"/>
+    /// by setting ONLY the canonical PascalCase <c>FullName</c> key — every other key is preserved verbatim.
+    /// This is the Galaxy address re-pick seam: re-picking an address must update the bound attribute WITHOUT
+    /// discarding fields the operator already edited independently of the address — ESPECIALLY a hand-authored
+    /// <c>alarm</c> object (and root history/array intent, scaling, etc.). Null/blank/malformed input starts
+    /// from a bare <c>{"FullName":...}</c> object.
+    /// </summary>
+    public static string SetFullName(string? json, string fullName)
+    {
+        var o = ParseOrNew(json);
+        o["FullName"] = JsonValue.Create(fullName);
+        return Serialize(o);
+    }
 }