fix: resolve TypeScript errors in mini-map and layer-effects-panel

- Add null check for layer.canvas before drawing in mini-map
- Change JSX.Element to React.ReactElement in layer-effects-panel
- Fixes deployment build errors

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

components/canvas/mini-map.tsx

@@ -64,9 +64,10 @@ export function MiniMap() {
     ctx.scale(scale, scale);
 
     layers
-      .filter((layer) => layer.visible)
+      .filter((layer) => layer.visible && layer.canvas)
       .sort((a, b) => a.order - b.order) // Bottom to top
       .forEach((layer) => {
+        if (!layer.canvas) return;
         ctx.globalAlpha = layer.opacity;
         ctx.drawImage(layer.canvas, layer.x, layer.y);
       });