fix: restore desktop startup and align tool previews with SDK updates

Add reflect-metadata bootstrap so desktop sidecar no longer crashes on startup.
Update SDK v1.4 compatibility for model variant and diff payload handling.
Unify write/edit/apply patch expanded previews and hide write success output noise.

packages/web/server/index.js

@@ -1,3 +1,4 @@
+import 'reflect-metadata';
 import express from 'express';
 import path from 'path';
 import { spawn, spawnSync } from 'child_process';