Support question-level LLM prompt

lib/cadet/assessments/question_types/programming_question.ex

@@ -13,13 +13,14 @@ defmodule Cadet.Assessments.QuestionTypes.ProgrammingQuestion do
     field(:template, :string)
     field(:postpend, :string, default: "")
     field(:solution, :string)
+    field(:llm_grading_prompt, :string, default: "")
     embeds_many(:public, Testcase)
     embeds_many(:opaque, Testcase)
     embeds_many(:secret, Testcase)
   end
 
   @required_fields ~w(content template)a
-  @optional_fields ~w(solution prepend postpend)a
+  @optional_fields ~w(solution prepend postpend llm_grading_prompt)a
 
   def changeset(question, params \\ %{}) do
     question

lib/cadet/jobs/xml_parser.ex

@@ -203,7 +203,8 @@ defmodule Cadet.Updater.XMLParser do
         prepend: ~x"./SNIPPET/PREPEND/text()" |> transform_by(&process_charlist/1),
         template: ~x"./SNIPPET/TEMPLATE/text()" |> transform_by(&process_charlist/1),
         postpend: ~x"./SNIPPET/POSTPEND/text()" |> transform_by(&process_charlist/1),
-        solution: ~x"./SNIPPET/SOLUTION/text()" |> transform_by(&process_charlist/1)
+        solution: ~x"./SNIPPET/SOLUTION/text()" |> transform_by(&process_charlist/1),
+        llm_grading_prompt: ~x"./LLM_GRADING_PROMPT/text()" |> transform_by(&process_charlist/1)
       ),
       entity
       |> xmap(