Storage Layout Visualiser

Works out which variables share a 32-byte slot and which force a new one, then compares the result against the best possible packing for the same types — the gap is wasted storage, fixable purely by reordering declarations, at roughly 20,000 gas per slot at deploy. Reads any variable from a live contract too, extracting its bytes from the packed word correctly: Solidity packs right to left, so a variable at offset N sits N bytes from the right end, not the left. You supply the declarations in source order, since deployed bytecode does not carry variable names. The comparison against optimal packing shows what reordering would save, at roughly twenty thousand gas per slot at deploy time and a cheaper write on every later update.