AI Implementation feature(888): Admin Area General Settings and Categories 1.06 (#28)

docs/api/admin.md

@@ -1,9 +1,9 @@
 ---
 type: api
 title: Admin Endpoints
-description: Admin-only endpoints for user management, general settings, categories, and supporting uploads.
+description: Admin-only endpoints for user management, required general settings, categories, and supporting uploads.
 tags: [api, admin, users, general, categories]
-timestamp: 2026-07-22T12:00:00Z
+timestamp: 2026-07-22T14:24:08Z
 ---
 
 # Endpoints
@@ -46,11 +46,13 @@ removes the row.
 * `logo` up to 2048 chars (a public URL — uploaded separately)
 * `welcomeMarkdown` up to 64 000 chars
 * `themeKey` is one of `THEME_IDS`
-* `eventStartUtc` / `eventEndUtc` are validated as ISO-8601 datetimes
-  (zod `string().datetime(...)`) — empty strings are explicitly allowed
-  to keep the event window unconfigured. `superRefine` then enforces
-  `eventEndUtc > eventStartUtc` and reports the issue on `eventEndUtc`
-  when both fields are non-empty.
+* `eventStartUtc` / `eventEndUtc` must each be non-empty ISO-8601
+  datetimes. Empty and malformed strings produce a field-specific
+  `400 VALIDATION_FAILED` issue (`eventStartUtc must be a valid ISO-8601
+  datetime` or `eventEndUtc must be a valid ISO-8601 datetime`).
+  `superRefine` additionally requires `eventEndUtc > eventStartUtc` and
+  reports `eventEndUtc must be strictly after eventStartUtc` on the end
+  field when both values parse but are out of order.
 * `defaultChallengeIp` 1–255 chars
 * `registrationsEnabled` boolean