improvement: support providing an input key in predicate maps

lib/ash/filter/filter.ex

@@ -2569,13 +2569,23 @@ defmodule Ash.Filter do
               {input || %{}, nested}
 
             nested ->
-              {%{}, nested}
+              cond do
+                is_map(nested) and Map.has_key?(nested, "input") ->
+                  {Map.get(nested, "input"), Map.delete(nested, "input")}
+
+                is_map(nested) and Map.has_key?(nested, :input) ->
+                  {Map.get(nested, :input), Map.delete(nested, :input)}
+
+                true ->
+                  {%{}, nested}
+              end
           end
 
         with {:ok, args} <-
                Ash.Query.validate_calculation_arguments(
                  resource_calculation,
-                 input
+                 input,
+                 !context[:input?]
                ),
              {:ok, calculation} <-
                Calculation.new(
@@ -3441,6 +3451,10 @@ defmodule Ash.Filter do
     parse_predicates([eq: value], field, context)
   end
 
+  defp parse_predicates(value, field, context) when value == %{} do
+    parse_predicates([eq: true], field, context)
+  end
+
   defp parse_predicates(%struct{} = value, field, context)
        when struct not in [Not, BooleanExpression, Ref, Call] do
     parse_predicates([eq: value], field, context)

lib/ash/query/query.ex

@@ -1446,7 +1446,7 @@ defmodule Ash.Query do
   end
 
   @doc false
-  def validate_calculation_arguments(calculation, args) do
+  def validate_calculation_arguments(calculation, args, allow_expr? \\ true) do
     args =
       if Keyword.keyword?(args) do
         Map.new(args)
@@ -1464,7 +1464,7 @@ defmodule Ash.Query do
         )
 
       cond do
-        expr?(value) && argument.allow_expr? ->
+        expr?(value) && argument.allow_expr? && allow_expr? ->
           {:cont,
            {:ok,
             Map.put(