Add dragging support to curved text

- Add x/y positioning and offset to TextPath for proper dragging
- Make TextPath draggable with onDragEnd handler
- Curved text can now be selected, moved, and toggled without issues
- Uses offset property to handle path-based positioning correctly

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/components/DesignCanvas.tsx

@@ -325,7 +325,7 @@ function PrintSurface({
               {elements.map((el) =>
                 el.type === 'text' ? (
                   el.curvedPath ? (
-                    // Curved text - simple TextPath without Group wrapper
+                    // Curved text - TextPath with dragging support
                     <TextPath
                       key={el.id}
                       ref={(node) => {
@@ -336,9 +336,17 @@ function PrintSurface({
                       fontFamily={el.fontFamily}
                       fontSize={el.fontSize}
                       fill={el.fill}
+                      offset={{ x: -el.x, y: -el.y }}
+                      x={el.x}
+                      y={el.y}
+                      draggable
                       listening={true}
                       onClick={() => setSelectedId(el.id)}
                       onTap={() => setSelectedId(el.id)}
+                      onDragEnd={(e) => {
+                        const node = e.target as any;
+                        updateElement(el.id, { x: node.x(), y: node.y() });
+                      }}
                     />
                   ) : (
                     // Regular straight text