Fix pattern dragging and vertical scrolling

app/page.tsx

@@ -611,7 +611,8 @@ export default function Home() {
     if (event.button !== 0) return;
     const stage = patternStageRef.current;
     if (!stage) return;
-    stage.setPointerCapture(event.pointerId);
+    suppressCanvasClickRef.current = false;
+    event.currentTarget.setPointerCapture(event.pointerId);
     patternDragRef.current = {
       pointerId: event.pointerId,
       x: event.clientX,
@@ -643,7 +644,23 @@ export default function Home() {
     suppressCanvasClickRef.current = drag.moved;
     patternDragRef.current = null;
     stage?.classList.remove("is-dragging");
-    if (stage?.hasPointerCapture(event.pointerId)) stage.releasePointerCapture(event.pointerId);
+    if (event.currentTarget.hasPointerCapture(event.pointerId)) event.currentTarget.releasePointerCapture(event.pointerId);
+  };
+
+  const handlePatternPointerCancel = (event: React.PointerEvent<HTMLCanvasElement>) => {
+    const drag = patternDragRef.current;
+    if (drag?.pointerId !== event.pointerId) return;
+    patternDragRef.current = null;
+    suppressCanvasClickRef.current = false;
+    patternStageRef.current?.classList.remove("is-dragging");
+    if (event.currentTarget.hasPointerCapture(event.pointerId)) event.currentTarget.releasePointerCapture(event.pointerId);
+  };
+
+  const handlePatternLostPointerCapture = (event: React.PointerEvent<HTMLCanvasElement>) => {
+    if (patternDragRef.current?.pointerId !== event.pointerId) return;
+    patternDragRef.current = null;
+    suppressCanvasClickRef.current = false;
+    patternStageRef.current?.classList.remove("is-dragging");
   };
 
   const handleCanvasClick = (event: React.MouseEvent<HTMLCanvasElement>) => {
@@ -662,6 +679,10 @@ export default function Home() {
   };
 
   const handleCanvasMove = (event: React.MouseEvent<HTMLCanvasElement>) => {
+    if (patternDragRef.current?.moved) {
+      setHoveredPixel(null);
+      return;
+    }
     const canvas = canvasRef.current;
     if (!canvas) return;
     const rect = canvas.getBoundingClientRect();
@@ -798,7 +819,9 @@ export default function Home() {
                 onPointerDown={handlePatternPointerDown}
                 onPointerMove={handlePatternPointerMove}
                 onPointerUp={handlePatternPointerUp}
-                onPointerCancel={handlePatternPointerUp}
+                onPointerCancel={handlePatternPointerCancel}
+                onLostPointerCapture={handlePatternLostPointerCapture}
+                onContextMenu={(event) => event.preventDefault()}
                 onClick={handleCanvasClick}
                 onMouseMove={handleCanvasMove}
                 onMouseLeave={() => setHoveredPixel(null)}