0.17.0: split SVG layer into per-path layers

Right-click an SVG-backed layer to split it into one layer per
top-level drawable. Each part keeps the original stage position
and ends up as a same-size standalone SVG.

Also: delete confirm now floats above the welcome dialog (topmost
z-index + scoped ESC/Tab via modal stack) and autofocuses its
primary button so Enter triggers confirm instead of bubbling back
to the underlying row.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

package.json

@@ -1,7 +1,7 @@
 {
   "name": "ruwio",
   "private": true,
-  "version": "0.16.1",
+  "version": "0.17.0",
   "type": "module",
   "scripts": {
     "dev": "vite",