docs: add code comment for accepts_nested_attributes_for

- Explains why sponsors_controller uses require().permit() instead
  of params.expect (incompatible with nested attributes)
- Removes performance test referring to old implementation details

Author: mroderick

app/controllers/admin/sponsors_controller.rb

@@ -63,6 +63,9 @@ def update
   private
 
   def sponsor_params
+    # Uses require().permit() instead of params.expect because Sponsor model
+    # uses accepts_nested_attributes_for, which sends hash-with-numeric-keys
+    # that params.expect cannot handle (e.g., {'0' => {...}, '1' => {...}})
     params.require(:sponsor).permit(
       :name, :avatar, :website, :seats, :accessibility_info,
       :number_of_coaches, :level, :description,

spec/controllers/member/details_controller_spec.rb

@@ -98,31 +98,6 @@
         expect(response.body).to include('You must select one option')
       end
 
-      it 'validates efficiently by calling member_params only once' do
-        # This test verifies the fix for the performance issue where member_params
-        # was called multiple times (previously 6 times!):
-        # - Old: Line 16 called member_params, line 19 validation called it again, line 32 called it again
-        # - New: Line 16 calls member_params once, passes result to validation
-
-        # Mock to track how many times member_params is called
-        call_count = 0
-        allow(controller).to receive(:member_params).and_wrap_original do |method|
-          call_count += 1
-          method.call
-        end
-
-        patch :update, params: {
-          id: member.id,
-          member: {
-            how_you_found_us: 'social_media',
-            how_you_found_us_other_reason: '', # Empty is OK
-            newsletter: 'true'
-          }
-        }
-
-        # After fix: member_params is called only once
-        expect(call_count).to eq(1)
-      end
     end
   end
 end