Grinder and Saw hopper blocks replace the Refiner and Stone cutter in the menu (t4)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/sim/save.js

@@ -37,7 +37,7 @@ function deserializeWorld(meta, buffers) {
   computeAmbient(); fillNoise();
   mat.set(buffers.mat); life.set(buffers.life); flags.set(buffers.flags);
   for (let i = 0; i < N; i++) if (mat[i] === SPRING) mat[i] = STONE; // springs are gone: older worlds keep plain rock there
-  blockP.set(buffers.blockP); blockV.set(buffers.blockV); filtersDirty = true;
+  blockP.set(buffers.blockP); blockV.set(buffers.blockV); filtersDirty = true; rebuildProcessors();
   // pipes used to be solid copper blocks; now they are thin and let things past
   for (let b = 0; b < NB; b++) if (blockP[b] === BP_PIPE) for (const i of blockCellList(b % BW, (b / BW) | 0)) if (mat[i] === PIPE) { mat[i] = EMPTY; part[i] = P_PIPE; }
   for (const [b, m, inv] of meta.filters || []) if (blockP[b] === BP_FILTER) filterCfg.set(b, filterRec({ m, inv }));