Expose user avatar URL field in the UI (#27)

* wip

* some fixes

* update readme

* update readme

* Add option to change/erase any user's avatar

* Fix README

* Remove mutationMode from Edit

* remove log

* update readme

src/synapse/synapse.ts

@@ -1,4 +1,4 @@
-import { fetchUtils } from "react-admin";
+import { Identifier, fetchUtils } from "react-admin";
 
 import storage from "../storage";
 
@@ -77,17 +77,17 @@ export function generateRandomMxId(): string {
  * @param input  the input string
  * @returns full MXID as string
  */
-export function returnMXID(input: string): string {
+export function returnMXID(input: string | Identifier): string {
   const homeserver = storage.getItem("home_server");
 
   // Check if the input already looks like a valid MXID (i.e., starts with "@" and contains ":")
   const mxidPattern = /^@[^@:]+:[^@:]+$/;
-  if (mxidPattern.test(input)) {
+  if (typeof input === 'string' && mxidPattern.test(input)) {
     return input; // Already a valid MXID
   }
 
   // If input is not a valid MXID, assume it's a localpart and construct the MXID
-  const localpart = input.startsWith('@') ? input.slice(1) : input;
+  const localpart = typeof input === 'string' && input.startsWith('@') ? input.slice(1) : input;
   return `@${localpart}:${homeserver}`;
 }