feat(renderer): polish gameplay visuals — transport, starfield, sparkles, smooth piece motion

Add transport/transfer effect for NEXT → grid with cross-fade and preview swap
Integrate in-grid Starfield3D with magnet targeting tied to active piece
Spawn ambient sparkles and impact sparks (hard-drop crackle + burst on expiry)
Smooth horizontal/fall interpolation for active piece (configurable smooth scroll)
Refactor next panel / preview rendering and connector drawing
Tweak stats/score panel layout, progress bars and typography for compact view
Preserve safe alpha handling and restore renderer blend/scale state after overlays

src/core/Settings.h

@@ -31,6 +31,10 @@ public:
 
     bool isSmoothScrollEnabled() const { return m_smoothScrollEnabled; }
     void setSmoothScrollEnabled(bool value) { m_smoothScrollEnabled = value; }
+
+    // Rotation behavior: should pressing UP rotate clockwise? (true = clockwise)
+    bool isUpRotateClockwise() const { return m_upRotateClockwise; }
+    void setUpRotateClockwise(bool value) { m_upRotateClockwise = value; }
     
     const std::string& getPlayerName() const { return m_playerName; }
     void setPlayerName(const std::string& name) { m_playerName = name; }
@@ -50,4 +54,6 @@ private:
     bool m_debugEnabled = false;
     bool m_smoothScrollEnabled = true;
     std::string m_playerName = "Player";
+    // Default: UP rotates clockwise
+    bool m_upRotateClockwise = true;
 };