add POST /artifacts/grade endpoint

allows grading artifact skills without persisting a record

app/controllers/api/v1/artifacts_controller.rb

@@ -19,6 +19,21 @@ module Api
         render json: ArtifactBlueprint.render(@artifact)
       end
 
+      # POST /artifacts/grade
+      # Grades artifact skills without persisting. Accepts skill data and returns grade/recommendation.
+      #
+      # @param artifact_id [String] Optional - ID of base artifact (for quirk detection)
+      # @param skill1 [Hash] Skill data with modifier, strength, level
+      # @param skill2 [Hash] Skill data with modifier, strength, level
+      # @param skill3 [Hash] Skill data with modifier, strength, level
+      # @param skill4 [Hash] Skill data with modifier, strength, level
+      def grade
+        artifact_data = build_gradeable_artifact
+        grader = ArtifactGrader.new(artifact_data)
+
+        render json: { grade: grader.grade }
+      end
+
       private
 
       def set_artifact
@@ -26,6 +41,29 @@ module Api
       rescue ActiveRecord::RecordNotFound
         render_not_found_response('artifact')
       end
+
+      def build_gradeable_artifact
+        base_artifact = params[:artifact_id].present? ? Artifact.find_by(id: params[:artifact_id]) : nil
+
+        # Build a simple struct that responds to what ArtifactGrader needs
+        OpenStruct.new(
+          skill1: grade_params[:skill1] || {},
+          skill2: grade_params[:skill2] || {},
+          skill3: grade_params[:skill3] || {},
+          skill4: grade_params[:skill4] || {},
+          artifact: base_artifact || OpenStruct.new(quirk?: false)
+        )
+      end
+
+      def grade_params
+        params.permit(
+          :artifact_id,
+          skill1: %i[modifier strength level],
+          skill2: %i[modifier strength level],
+          skill3: %i[modifier strength level],
+          skill4: %i[modifier strength level]
+        )
+      end
     end
   end
 end

config/routes.rb

@@ -102,7 +102,11 @@ Rails.application.routes.draw do
     resources :weapon_series, only: %i[index show create update destroy]
 
     # Artifacts (read-only reference data)
-    resources :artifacts, only: %i[index show]
+    resources :artifacts, only: %i[index show] do
+      collection do
+        post :grade
+      end
+    end
     resources :artifact_skills, only: %i[index] do
       collection do
         get 'for_slot/:slot', action: :for_slot, as: :for_slot