F on an ingot mold does nothing and says nothing

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

src/sim/actions.js

@@ -73,7 +73,8 @@ function interactAt(x, y) {
   const g = toggleGateAt(x, y);
   if (g) { emit({ t: 'sfx', s: 'gate' }); return g === 'open' ? 'Gate opened.' : 'Gate closed.'; }
   const mo = moldAt(x, y);
-  if (mo) { const r = collectMold(mo); if (mo.kind !== 'ingot' && !r.startsWith('New') && !r.startsWith('Knocked')) emit({ t: 'sfx', s: 'ui' }); return r; }
+  // ingot molds empty themselves: F passes them by
+  if (mo && mo.kind !== 'ingot') { const r = collectMold(mo); if (!r.startsWith('New') && !r.startsWith('Knocked')) emit({ t: 'sfx', s: 'ui' }); return r; }
   const pb = ((y / BS) | 0) * BW + ((x / BS) | 0);
   if (blockP[pb] === BP_PUMP || blockP[pb] === BP_OUTLET) {
     blockV[pb] ^= 4; emit({ t: 'sfx', s: 'ui' });

src/ui/actions.js

@@ -43,7 +43,7 @@ function doInteract() {
     if (msg) break outer;
   }
   if (msg) { setStatus(msg, 'info'); if (!/^New (drill bit|bag)/.test(msg)) toast(msg); }
-  else { setStatus('Nothing to use there.', 'info'); }
+  else if ((moldAt(ax, ay) || {}).kind !== 'ingot') setStatus('Nothing to use there.', 'info'); // an ingot mold needs no F: say nothing
 }
 // Pick (middle mouse): the piece under the cursor becomes the one you build, with its
 // direction, wall material and filter settings. On loose material it picks that to blow out.