Inline the one-line beltLike wrapper (t85)

Written by the local model (qwen3-coder-30b) in a sandboxed worktree via local-run; reviewed by Claude.

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

src/render/cell.js

@@ -173,7 +173,7 @@ function cellPixel(x, y) {
       } else if (ly === 3) { // the belt's return run carries on under it, so belts and filters read as one belt
         const st = ((x - dir * (anim >> 1)) >> 1) & 1;
         if (m === EMPTY || st) { r = (st ? 92 : 56) * 0.72; g = (st ? 96 : 58) * 0.72; b = (st ? 104 : 66) * 0.72; }
-      } else if ((lx === 0 && !beltLike(fb, 0)) || (lx === 3 && !beltLike(fb, 1))) { if (m === EMPTY || ((x + y) & 1)) { r = 64; g = 66; b = 74; } } // frame only where the line ends
+      } else if ((lx === 0 && endJoin(fb % BW, (fb / BW) | 0, 0) < 0) || (lx === 3 && endJoin(fb % BW, (fb / BW) | 0, 1) < 0)) { if (m === EMPTY || ((x + y) & 1)) { r = 64; g = 66; b = 74; } } // frame only where the line ends
       else if (m === EMPTY) { // mesh holes, tinted with what falls through them
         if ((x + y) & 1) { r = 40; g = 42; b = 48; }
         else if (inv) { r = 58; g = 74; b = 72; } // carry mode: everything else drops

src/render/setup.js

@@ -116,8 +116,6 @@ function thinPipeColor(x, y, anim) {
   }
   PC[0] = r; PC[1] = g; PC[2] = bl;
 }
-// A filter frame opens only where this end has a geometric partner.
-function beltLike(b, end) { return endJoin(b % BW, (b / BW) | 0, end) >= 0; }
 // standing trees: the trunk shows its dark bark, so it reads apart from the pale cut wood it drops
 const TREE_R = new Uint8Array(NMAT), TREE_G = new Uint8Array(NMAT), TREE_B = new Uint8Array(NMAT);
 for (let m = 0; m < NMAT; m++) { TREE_R[m] = COLR[m]; TREE_G[m] = COLG[m]; TREE_B[m] = COLB[m]; }