Fix custom parser OpenAPI types and add structured default response schema

Agent-Logs-Url: https://github.com/fosrl/pangolin/sessions/73990123-9c27-444b-bc6e-77e890a0d57c

Co-authored-by: oschwartz10612 <4999704+oschwartz10612@users.noreply.github.com>

server/private/routers/approvals/processPendingApproval.ts

@@ -24,7 +24,7 @@ import type { NextFunction, Request, Response } from "express";
 
 const paramsSchema = z.strictObject({
     orgId: z.string(),
-    approvalId: z.string().transform(Number).pipe(z.int().positive())
+    approvalId: z.coerce.number().int().positive()
 });
 
 const bodySchema = z.strictObject({