Route terminal clipboard through tauri-plugin-clipboard-manager; bump to 0.2.3

navigator.clipboard.readText() triggers WebView2's "Allow clipboard access?"
permission prompt on every paste. The plugin goes through IPC + the OS
clipboard directly, so the prompt never fires.

Wired the Rust plugin, granted clipboard-manager:allow-{read,write}-text in
the capabilities manifest, swapped XtermPane's copy/paste handler to use
the plugin's readText/writeText.

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

src-tauri/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://schema.tauri.app/config/2",
   "productName": "tiletopia",
-  "version": "0.2.2",
+  "version": "0.2.3",
   "identifier": "com.megaproxy.tiletopia",
   "build": {
     "beforeDevCommand": "pnpm dev",