feat: keep dev server alive during HMR updates

packages/cli/src/update.ts

@@ -264,6 +264,14 @@ const MIGRATIONS: Migration[] = [
       if (!ctx.dryRun) writeFileSync(file, VSCODE_EXTENSIONS, "utf8");
     },
   },
+  {
+    version: "0.2.21",
+    id: "in-process-hmr-runtime",
+    description: "No project-file changes; the in-process HMR behavior is runtime-only",
+    apply() {
+      // Explicit no-op: updating @wrnexus/dev-server is sufficient.
+    },
+  },
 ];
 
 /** Release tooling uses this to require an explicit migration entry per version. */