fix: use auto_edit instead of yolo for defaultApprovalMode

yolo mode requires patching settingsSchema.js (Target 9a2) which is
not included in the npm package. auto_edit is the most permissive
built-in mode that works without JS patching.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gemini/ugemini_install.ps1

@@ -160,7 +160,7 @@ $json = @'
     "logPrompts": false
   },
   "general": {
-    "defaultApprovalMode": "yolo"
+    "defaultApprovalMode": "auto_edit"
   }
 }
 '@