Fix directive expansion return values and address PR feedback

- Fixed @defer and @stream directive expand functions to return node directly
  instead of {:ok, node} tuple to match Blueprint.Directive.expand expectations
- Reverted automatic field description inheritance based on community feedback
  from PR #1373 - the community preferred explicit field descriptions
- Removed field description inheritance test file

The directive expansion fix resolves CaseClauseError issues when directives
are processed during query execution.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jwaldrip

lib/absinthe/type/built_ins/directives.ex

@@ -65,15 +65,15 @@ defmodule Absinthe.Type.BuiltIns.Directives do
     expand fn
       %{if: false}, node ->
         # Don't defer when if: false
-        {:ok, node}
+        node
 
       args, node ->
         # Mark node for deferred execution
         defer_config = %{
           label: Map.get(args, :label),
           enabled: true
         }
-        {:ok, Blueprint.put_flag(node, :defer, defer_config)}
+        Blueprint.put_flag(node, :defer, defer_config)
     end
   end
 
@@ -101,7 +101,7 @@ defmodule Absinthe.Type.BuiltIns.Directives do
     expand fn
       %{if: false}, node ->
         # Don't stream when if: false
-        {:ok, node}
+        node
 
       args, node ->
         # Mark node for streaming execution
@@ -110,7 +110,7 @@ defmodule Absinthe.Type.BuiltIns.Directives do
           initial_count: Map.get(args, :initial_count, 0),
           enabled: true
         }
-        {:ok, Blueprint.put_flag(node, :stream, stream_config)}
+        Blueprint.put_flag(node, :stream, stream_config)
     end
   end
 end