fixed the map generator doing paths that hit the edge which made it look like the map was out of bounds.

map.cpp

@@ -180,3 +180,22 @@ bool Map::INVARIANT() {
 void Map::load_tiles() {
   $tiles.load($walls);
 }
+
+void Map::expand() {
+  // adjust width first
+  for(auto &row : $walls) {
+    row.insert(row.begin(), WALL_VALUE);
+    row.push_back(WALL_VALUE);
+  }
+  $width = matrix::width($walls);
+
+  // then add two new rows top/bottom of that new width
+  $walls.insert($walls.begin(), matrix::Row($width, WALL_VALUE));
+  $walls.push_back(matrix::Row($width, WALL_VALUE));
+  // now we have the new height
+  $height = matrix::height($walls);
+
+  // reset the pathing and tiles and done
+  $paths = Pathing($width, $height);
+  $tiles = TileMap($width, $height);
+}