feat: review open answers in the admin and pick a grader per quiz

- Do oceny admin screen (golem15.quizzes.reviews) over the open answers,
  with a read-only context partial, score and comment virtual fields saved
  through SetScore, confirm and regrade record actions, bulk confirm
- open question type, rubric and max_length in the question form; grader
  dropdown on the quiz form from the grader registry
- Review model with quiz, status and student filters

models/reviews/columns.yaml

@@ -0,0 +1,21 @@
+columns:
+    question:
+        label: golem15.quizzes::lang.reviews.question
+        relation: question
+        select: text
+        searchable: true
+    grading_status:
+        label: golem15.quizzes::lang.reviews.status
+    grader_points:
+        label: golem15.quizzes::lang.reviews.grader_points
+    points:
+        label: golem15.quizzes::lang.reviews.points
+    graded_at:
+        label: golem15.quizzes::lang.reviews.graded_at
+        type: datetime
+    reviewed_at:
+        label: golem15.quizzes::lang.reviews.reviewed_at
+        type: datetime
+    updated_at:
+        label: golem15.quizzes::lang.common.updated_at
+        type: datetime

models/reviews/fields.yaml

@@ -0,0 +1,19 @@
+# The answer itself is read-only: the review_context partial shows it from a
+# curated view model. review_points and review_comment are virtual fields the
+# controller saves through the review service (SetScore).
+fields:
+    review_context:
+        label: golem15.quizzes::lang.reviews.context
+        type: partial
+        path: review_context
+        span: full
+    review_points:
+        label: golem15.quizzes::lang.reviews.review_points
+        type: number
+        span: left
+        comment: golem15.quizzes::lang.reviews.review_points_comment
+    review_comment:
+        label: golem15.quizzes::lang.reviews.review_comment
+        type: textarea
+        size: small
+        comment: golem15.quizzes::lang.reviews.review_comment_comment