Improve question review and image handling

tests/media_viewer_test.gd

@@ -0,0 +1,57 @@
+extends SceneTree
+
+var failures := 0
+
+
+func _initialize() -> void:
+	_test_loaded_media_navigation()
+	_test_zoom_limits()
+	_test_image_question_detection()
+	quit(1 if failures > 0 else 0)
+
+
+func _test_loaded_media_navigation() -> void:
+	var player = load("res://scripts/ui/question_player.gd").new()
+	player.question_media_items = [
+		{"loaded": true},
+		{"loaded": false},
+		{"loaded": true}
+	]
+	_assert(player._find_loaded_media_index(0, 1) == 2, "navigation should skip images that have not loaded")
+	_assert(player._find_loaded_media_index(2, -1) == 0, "back navigation should preserve source order")
+	_assert(player._find_loaded_media_index(2, 1) == -1, "navigation should stop at the final image")
+	player.free()
+
+
+func _test_zoom_limits() -> void:
+	var player = load("res://scripts/ui/question_player.gd").new()
+	player.media_viewer_scroll = ScrollContainer.new()
+	player.media_viewer_scroll.size = Vector2(800, 600)
+	player.media_viewer_center = CenterContainer.new()
+	player.media_viewer_texture = TextureRect.new()
+	player.media_viewer_zoom_label = Label.new()
+	var image := Image.create(100, 50, false, Image.FORMAT_RGBA8)
+	player.media_viewer_texture.texture = ImageTexture.create_from_image(image)
+	player._set_media_viewer_zoom(20.0)
+	_assert(is_equal_approx(player.media_viewer_zoom, 4.0), "zoom should be capped at 400 percent")
+	player._set_media_viewer_zoom(0.01)
+	_assert(is_equal_approx(player.media_viewer_zoom, 0.25), "zoom should be capped at 25 percent")
+	player.media_viewer_scroll.free()
+	player.media_viewer_center.free()
+	player.media_viewer_texture.free()
+	player.media_viewer_zoom_label.free()
+	player.free()
+
+
+func _test_image_question_detection() -> void:
+	var service = load("res://scripts/autoload/question_bank_service.gd").new()
+	_assert(not service._contains_question_with_media([{"id": "plain", "media": []}]), "plain questions should not satisfy an image-only request")
+	_assert(service._contains_question_with_media([{"id": "image", "media": ["/media/example"]}]), "questions with media should satisfy an image-only request")
+	service.free()
+
+
+func _assert(condition: bool, message: String) -> void:
+	if condition:
+		return
+	failures += 1
+	push_error(message)

tests/media_viewer_test.gd.uid

@@ -0,0 +1 @@
+uid://b34pl1b02ehr6

tests/post_answer_review_test.gd

@@ -7,6 +7,7 @@ func _initialize() -> void:
 	_test_reference_normalization()
 	_test_reference_url_filter()
 	_test_correct_feedback_does_not_auto_advance()
+	_test_correct_review_locks_answer_interactions()
 	quit(1 if failures > 0 else 0)
 
 
@@ -58,6 +59,21 @@ func _test_correct_feedback_does_not_auto_advance() -> void:
 	player.free()
 
 
+func _test_correct_review_locks_answer_interactions() -> void:
+	var player = load("res://scripts/ui/question_player.gd").new()
+	player.current_answer = {"is_correct": true}
+	player.selected_choice = "A"
+	player.presented_choices = [{"id": "A", "text": "First"}, {"id": "B", "text": "Second"}]
+	player._select_choice(1)
+	_assert(player.selected_choice == "A", "correct review should reject answer selection changes")
+	var right_click := InputEventMouseButton.new()
+	right_click.button_index = MOUSE_BUTTON_RIGHT
+	right_click.pressed = true
+	player._choice_gui_input(right_click, 1)
+	_assert(player.eliminated.is_empty(), "correct review should reject answer strike-through changes")
+	player.free()
+
+
 func _assert(condition: bool, message: String) -> void:
 	if condition:
 		return