fix: widen resize handles and grab zones for easier node resizing

Increase resize handle hit area from 8px to 16px (edge handles) and
from 3px to 5px (corner handles) so they're easier to grab.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/globals.css

@@ -124,13 +124,13 @@ body {
 .react-flow__resize-control.left,
 .react-flow__resize-control.right {
   cursor: ew-resize !important;
-  width: 8px !important;
+  width: 16px !important;
 }
 
 .react-flow__resize-control.top,
 .react-flow__resize-control.bottom {
   cursor: ns-resize !important;
-  height: 8px !important;
+  height: 16px !important;
 }
 
 .react-flow__resize-control.top.left,

src/components/nodes/BaseNode.tsx

@@ -189,7 +189,7 @@ export function BaseNode({
         minWidth={minWidth}
         minHeight={minHeight}
         lineClassName="!border-transparent"
-        handleClassName="!w-3 !h-3 !bg-transparent !border-none"
+        handleClassName="!w-5 !h-5 !bg-transparent !border-none"
         onResize={handleResize}
       />
       <div