Add Zod validation to all API endpoints and remove debug test route

Adds schema-based input validation across helcim, events, members,
series, admin, and updates API endpoints. Removes the peer-support
debug test endpoint. Adds validation test coverage.

server/api/events/[id]/check-registration.post.js

@@ -2,16 +2,9 @@ import Event from "../../../models/event";
 
 export default defineEventHandler(async (event) => {
   const id = getRouterParam(event, "id");
-  const body = await readBody(event);
+  const body = await validateBody(event, checkRegistrationSchema);
   const { email } = body;
 
-  if (!email) {
-    throw createError({
-      statusCode: 400,
-      statusMessage: "Email is required",
-    });
-  }
-
   try {
     // Check if id is a valid ObjectId or treat as slug
     const isObjectId = /^[0-9a-fA-F]{24}$/.test(id);