Protect object corners during color cleanup

app/page.tsx

@@ -272,25 +272,36 @@ function cleanLowConfidenceIsolatedColors(
       const protectedDetail = current.lab[0] < 0.32 || current.lab[0] > 0.96 || chroma > 0.14;
       if (protectedDetail) continue;
 
-      const neighborCounts = new Map<string, { color: BeadColor; count: number }>();
+      const neighborCounts = new Map<string, { color: BeadColor; count: number; confidentCount: number }>();
       let neighborTotal = 0;
+      let sameColorNeighbors = 0;
       for (const rowOffset of offsets) {
         for (const columnOffset of offsets) {
           if (rowOffset === 0 && columnOffset === 0) continue;
           const neighborRow = row + rowOffset;
           const neighborColumn = column + columnOffset;
           if (neighborRow < 0 || neighborColumn < 0 || neighborRow >= height || neighborColumn >= width) continue;
-          const neighbor = colors[neighborRow * width + neighborColumn];
-          const entry = neighborCounts.get(neighbor.code) ?? { color: neighbor, count: 0 };
+          const neighborIndex = neighborRow * width + neighborColumn;
+          const neighbor = colors[neighborIndex];
+          if (neighbor.code === current.code) sameColorNeighbors += 1;
+          const entry = neighborCounts.get(neighbor.code) ?? { color: neighbor, count: 0, confidentCount: 0 };
           entry.count += 1;
+          if (confidence[neighborIndex] >= 0.625) entry.confidentCount += 1;
           neighborCounts.set(neighbor.code, entry);
           neighborTotal += 1;
         }
       }
+      // A boundary corner is still part of a continuous object. Only a color with
+      // no same-color support in all eight neighboring cells counts as isolated.
+      if (sameColorNeighbors > 0) continue;
       const majority = [...neighborCounts.values()].sort((a, b) => b.count - a.count)[0];
       if (!majority || majority.color.code === current.code) continue;
       const requiredCount = neighborTotal >= 7 ? 5 : Math.max(2, Math.ceil(neighborTotal * 0.67));
       if (majority.count < requiredCount) continue;
+      if (majority.confidentCount < Math.min(3, majority.count)) continue;
+      // Large color jumps describe a real object boundary rather than an
+      // anti-aliased transition color, so never let cleanup cross that edge.
+      if (oklabDistance(current.lab, majority.color.lab) > 0.075) continue;
       cleaned[index] = majority.color;
       changed += 1;
     }