fix: gate passive update check behind explicit env flag

packages/opencode/src/cli/upgrade.ts

@@ -6,9 +6,9 @@ import { InstallationVersion } from "@opencode-ai/core/installation/version"
 import { GlobalBus } from "@/bus/global"
 
 export async function upgrade() {
-  // Neuron fork: update checks are opt-in. We do not phone home by default.
-  const config = await AppRuntime.runPromise(Config.Service.use((cfg) => cfg.getGlobal()))
-  if (config.autoupdate !== true || Flag.OPENCODE_DISABLE_AUTOUPDATE) return
+  // Neuron fork: the passive update check is disabled. Set
+  // OPENCODE_ALWAYS_NOTIFY_UPDATE=1 to re-enable release notifications.
+  if (!Flag.OPENCODE_ALWAYS_NOTIFY_UPDATE) return
   const method = await Installation.method()
   const latest = await Installation.latest(method).catch(() => {})
   if (!latest) return