fix(tauri): disable freezePrototype to fix xterm.js crash

xterm.js modifies JavaScript prototypes during initialization, which
fails when freezePrototype is enabled in Tauri's security settings.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: fazxes

src-tauri/tauri.conf.json

@@ -38,7 +38,7 @@
         "frame-src": "'none'",
         "object-src": "'none'"
       },
-      "freezePrototype": true,
+      "freezePrototype": false,
       "dangerousDisableAssetCspModification": false
     }
   },