fix: avoid unnecessary macOS folder prompts on desktop startup

Start managed OpenCode from the app data directory instead of the home folder
Prevent unnecessary Desktop, Documents, Downloads, and Music access prompts
Add coverage for configured OpenCode working directory

packages/electron/main.mjs

@@ -1089,7 +1089,12 @@ const spawnLocalServer = async () => {
   process.env.OPENCHAMBER_HOST = bindHost;
   process.env.OPENCHAMBER_DIST_DIR = resolveWebDistDir();
   process.env.OPENCHAMBER_RUNTIME = 'desktop';
+  process.env.OPENCHAMBER_OPENCODE_CWD = app.getPath('userData');
   process.env.OPENCHAMBER_DESKTOP_NOTIFY = 'true';
+  try {
+    fs.mkdirSync(process.env.OPENCHAMBER_OPENCODE_CWD, { recursive: true });
+  } catch {
+  }
   if (desktopUiPassword) {
     process.env.OPENCHAMBER_UI_PASSWORD = desktopUiPassword;
   } else {