[qa] Fix merge conflicts and formatting issues

- Resolve remaining git conflict markers in admin.py
- Fix whitespace issue in serializers.py
- Format rest-api.rst documentation

Author: Eeshu-Yadav

docs/user/rest-api.rst

@@ -857,7 +857,7 @@ When using this strategy, in the response you can find the field
 credentials.
 
 Batch retrieve and update
-++++++++++++++++++++++++++
++++++++++++++++++++++++++
 
 .. code-block:: text
 
@@ -870,16 +870,16 @@ Used to retrieve or update a ``RadiusBatch`` instance.
 .. note::
 
     The ``organization`` field is **read-only** for existing batch objects
-    and cannot be changed via the API. This is intentional as changing
-    the organization after batch creation would be inconsistent.
+    and cannot be changed via the API. This is intentional as changing the
+    organization after batch creation would be inconsistent.
 
 Parameters for **GET**:
 
-===== ===========
+===== =================
 Param Description
-===== ===========
+===== =================
 id    UUID of the batch
-===== ===========
+===== =================
 
 Parameters for **PUT**/**PATCH** (only certain fields can be updated):
 

openwisp_radius/admin.py

@@ -463,9 +463,7 @@ def delete_selected_batches(self, request, queryset):
         )
 
     def get_readonly_fields(self, request, obj=None):
-        readonly_fields = super(RadiusBatchAdmin, self).get_readonly_fields(
-            request, obj
-        )
+        readonly_fields = super().get_readonly_fields(request, obj)
         if obj and obj.status != "pending":
             return (
                 "strategy",
@@ -476,7 +474,6 @@ def get_readonly_fields(self, request, obj=None):
                 "users",
                 "expiration_date",
                 "name",
-                "organization",
                 "status",
             ) + readonly_fields
         elif obj:

openwisp_radius/api/serializers.py

@@ -537,7 +537,7 @@ def validate(self, data):
         """
         # Remove organization_slug from data if provided (should not be changeable)
         data.pop("organization_slug", None)
-        
+
         strategy = data.get("strategy") or (self.instance and self.instance.strategy)
 
         if (