Add zod payload contracts for admin API routes (#358)

* Add zod route payload contracts for admin APIs

* Fix review follow-ups for zod admin payloads

* Refactor account payload parser helpers

package-lock.json

@@ -31,7 +31,8 @@
         "pg": "^8.16.3",
         "socks": "^2.8.7",
         "undici": "^6.24.1",
-        "ws": "^8.20.0"
+        "ws": "^8.20.0",
+        "zod": "^4.3.6"
       },
       "devDependencies": {
         "@electron/notarize": "^3.1.0",
@@ -17177,6 +17178,15 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/zod": {
+      "version": "4.3.6",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.3.6.tgz",
+      "integrity": "sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/colinhacks"
+      }
+    },
     "node_modules/zwitch": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/zwitch/-/zwitch-2.0.4.tgz",