feat(entity-manager): reload del nivell + PaintLayer::clear

source/game/map/paint_layer.cpp

@@ -82,6 +82,13 @@ auto PaintLayer::isPainted(int col, int row) const -> bool {
     return painted_[static_cast<std::size_t>(row)][static_cast<std::size_t>(col)] >= 0;
 }
 
+void PaintLayer::clear() {
+    // Mateixa geometria que al ctor: matriu de tiles a -1 (no pintat) i
+    // buffer ARGB a zero (alpha=0 = transparent → render no escriu res).
+    painted_.assign(static_cast<std::size_t>(rows_), std::vector<int>(static_cast<std::size_t>(cols_), -1));
+    std::ranges::fill(pixels_, 0U);
+}
+
 auto PaintLayer::tryPaint(int col, int row, int tile_index, int player_id) -> bool {
     if (col < 0 || col >= cols_ || row < 0 || row >= rows_) { return false; }
     if (tile_index < 0) { return false; }