Polish question player header/toolbar and add configurable block size

- Fix the toolbar wrapping onto two rows: its minimum width was tuned
  for an older, narrower button set and never widened back out after
  reverting to bare icon buttons.
- Drop the "Time elapsed"/"Ctrl+Enter" readout next to Submit - it was
  clutter; the underlying timer logic keeps running unseen.
- Move the RanaZe brand mark above the question-count row instead of
  sharing a line with it.
- Progress text drops the word "Question" everywhere ("1 of 10"), and
  core/dynamic sessions now cycle against a configurable block size
  (Settings > Question block size, default 10) instead of counting up
  forever.

scripts/autoload/block_session_service.gd

@@ -28,10 +28,41 @@ var simulation_block_index := 0
 var simulation_total_blocks := 12
 var simulation_deadline_unix := 0.0
 var review_first_submission_recorded := false
+var core_block_size := DEFAULT_CORE_BLOCK_SIZE
 
 const CORE_MIN_TARGET_SECONDS := 45.0
 const CORE_MAX_TARGET_SECONDS := 150.0
 const CORE_RETRY_TARGET_SECONDS := 30.0
+const DEFAULT_CORE_BLOCK_SIZE := 10
+const CORE_BLOCK_SIZE_MIN := 5
+const CORE_BLOCK_SIZE_MAX := 40
+const SETTINGS_PATH := "user://settings.cfg"
+const SETTINGS_SECTION := "session"
+const SETTINGS_KEY_CORE_BLOCK_SIZE := "core_block_size"
+
+
+func _ready() -> void:
+	_load_core_block_size()
+
+
+func set_core_block_size(value: int) -> void:
+	var clamped := clampi(value, CORE_BLOCK_SIZE_MIN, CORE_BLOCK_SIZE_MAX)
+	if clamped == core_block_size:
+		return
+	core_block_size = clamped
+	var config := ConfigFile.new()
+	config.load(SETTINGS_PATH)
+	config.set_value(SETTINGS_SECTION, SETTINGS_KEY_CORE_BLOCK_SIZE, core_block_size)
+	if config.save(SETTINGS_PATH) != OK:
+		push_warning("Unable to save core question block size preference.")
+
+
+func _load_core_block_size() -> void:
+	var config := ConfigFile.new()
+	if config.load(SETTINGS_PATH) == OK:
+		core_block_size = clampi(
+			int(config.get_value(SETTINGS_SECTION, SETTINGS_KEY_CORE_BLOCK_SIZE, DEFAULT_CORE_BLOCK_SIZE)),
+			CORE_BLOCK_SIZE_MIN, CORE_BLOCK_SIZE_MAX)
 
 
 func start_dynamic_question(question: Dictionary) -> bool: