feat(confidence-engine): establish authenticated product boundary

app/api/focused-investigation/deconstruct/route.js

@@ -4,8 +4,9 @@ import {
   focusedDeconstructJsonSchema,
   validateFocusedDeconstructSchema,
 } from "@/lib/graph/focused-investigation";
+import { withAuthenticatedApi } from "@/lib/supabase/api-auth.js";
 
-export async function POST(request) {
+async function post(request) {
   let targetNodeId = null;
   let startedAt = null;
   try {
@@ -152,3 +153,5 @@ export async function POST(request) {
     );
   }
 }
+
+export const POST = withAuthenticatedApi(post);