Pin Turbopack root to app dir to stop dev recompile loop

Two package-lock.json files exist (parent civi-webform/ + this app);
Next 16 silently picked the outer one, so Turbopack watched the parent
node_modules/, .claude-flow/, .swarm/, ruvector.db. Background writes
in those trees triggered a recompile loop that thrashed .next/dev and
leaked memory until the dev server crashed. Setting turbopack.root
keeps the watcher scoped to WebForm-mw/.

next.config.ts

@@ -1,3 +1,4 @@
+import path from "node:path";
 import type { NextConfig } from "next";
 
 /**
@@ -49,6 +50,16 @@ const securityHeaders = [
 const nextConfig: NextConfig = {
   poweredByHeader: false,
   reactStrictMode: true,
+  // Pin Turbopack's filesystem root to THIS app's directory. Without this,
+  // Next 16 walks up to the parent civi-webform/ workspace (it sees two
+  // package-lock.json files and silently picks the outer one), which causes
+  // Turbopack to watch the parent node_modules/, .claude-flow/, .swarm/, and
+  // ruvector.db. Background writes in those trees trigger a recompile loop:
+  // compile → write .next/dev → re-trigger → memory blows up. The build-time
+  // warning surfaces the same issue.
+  turbopack: {
+    root: path.resolve(__dirname),
+  },
   async headers() {
     return [{ source: "/:path*", headers: securityHeaders }];
   },