feat: v0.2.0 - add system tray, clean up unused role field

- Replace text '+' icon with centered SVG plus icon for the add-provider button
- Add system tray: minimize-to-tray and quit-from-tray menu (minimize hides window, close exits app)
- Remove unused model role field (no functional effect, only stored/displayed)
- Fix multiple providers showing as active in Kimi Code mode: only the default_model's provider is marked active
- Copy /reload to clipboard after provider switch as a convenience hint
- Bump version to 0.2.0

package.json

@@ -1,7 +1,7 @@
 {
-  "name": "piswitch",
+  "name": "kimiswitch",
   "private": true,
-  "version": "0.1.0",
+  "version": "0.2.0",
   "type": "module",
   "scripts": {
     "dev": "vite",