Bump version to 0.2.1

Changes since 0.2.0:
- Fix broadcast no-op (useEffect deps captured stale orch ref, so paneIds
  got silently unregistered on every click → broadcastFrom found no peers)
- Flat-list layout architecture: render leaves as siblings keyed by id,
  position via absolute boxes. PTYs survive any tree reshape.
- Drag a pane's toolbar onto another pane to swap them
- Idle reporting moved out of toast spam into a "N idle" titlebar badge
  + red pane border + red "idle" status text
- Themed terminal scrollbars
- Global 📡 broadcast toggle in the titlebar
- Presets preserve existing panes' shells (only kill what overflows the
  preset's slot count, with a confirm dialog)
- React 18 frontend (Svelte version retired to svelte-archive branch)

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

package.json

@@ -1,7 +1,7 @@
 {
   "name": "tiletopia",
   "private": true,
-  "version": "0.2.0",
+  "version": "0.2.1",
   "type": "module",
   "scripts": {
     "dev": "vite",