fix: prevent null crash on entityName.trim() with type check - #34

Problem

In app/api/wallet-set/route.ts, if entityName is missing from the request body, .trim() throws a TypeError before validation can run:

const { entityName } = await req.json();

if (!entityName.trim()) {  // 💥 TypeError if entityName is undefined
  return NextResponse.json({ error: "entityName is required" }, { status: 400 });
}

This causes an unhandled 500 instead of returning a proper 400 response.

Fix

Added a type check before calling .trim():

- if (!entityName.trim()) {
+ if (typeof entityName !== "string" || !entityName.trim()) {
    return NextResponse.json(
-     { error: "entityName is required" },
+     { error: "entityName is required and must be a non-empty string" },
      { status: 400 }
    );
  }

The typeof check safely handles undefined, null, numbers, and any other non-string value before .trim() is ever called.

Impact

• Correctness: Returns proper 400 instead of unhandled 500
• Risk: Low — additive validation, no breaking changes