Remove JsonSerializerService and update related tests

spec/requests/api/units_json_inspection_history_spec.rb

@@ -83,9 +83,10 @@
       expect(unit_with_inspections.inspections.first.complete?).to eq(true)
     end
 
-    it "returns correct data when called directly on model" do
-      # Test the serializer directly
-      json = JsonSerializerService.serialize_unit(unit.reload)
+    it "returns correct data through the API endpoint" do
+      # Test through the actual endpoint
+      get "/units/#{unit.id}.json"
+      json = JSON.parse(response.body, symbolize_names: true)
 
       expect(json[:inspection_history]).to be_present
       expect(json[:inspection_history].length).to eq(1)

spec/requests/api/units_json_real_world_spec.rb

@@ -64,10 +64,6 @@
         found_unit = Unit.find_by(id: unit.id.upcase)
         expect(found_unit).to eq(unit)
 
-        # Test serializer directly with the found unit
-        json = JsonSerializerService.serialize_unit(found_unit)
-        expect(json[:inspection_history]).to be_present
-
         # Now test through the actual endpoint
         get "/units/#{unit.id}.json"
         response_json = JSON.parse(response.body)

spec/requests/inspections/inspections_spec.rb

@@ -741,11 +741,14 @@ def mock_failing_update(error_messages = ["Update error"])
       end
 
       it "serves JSON via .json format" do
-        allow(JsonSerializerService).to receive(:serialize_inspection).and_return({id: inspection.id})
-
         get "/inspections/#{inspection.id}.json"
         expect(response).to have_http_status(:success)
         expect(response.content_type).to include("application/json")
+
+        json = JSON.parse(response.body)
+        expect(json).to be_present
+        expect(json).to have_key("complete")
+        expect(json).to have_key("urls")
       end
 
       it "serves QR code via .png format" do