config: add matrix.org + mozilla.org homeservers, allow custom

matrix.lotusguild.org remains the default (index 0). matrix.org and
mozilla.org added as dropdown options. allowCustomHomeservers: true
lets users type any homeserver address for friends on other servers.

Also applied directly to /var/www/html/config.json — live immediately,
no deploy needed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/config.json

@@ -1,7 +1,7 @@
 {
   "defaultHomeserver": 0,
-  "homeserverList": ["matrix.lotusguild.org"],
+  "homeserverList": ["matrix.lotusguild.org", "matrix.org", "mozilla.org"],
-  "allowCustomHomeservers": false,
+  "allowCustomHomeservers": true,
   "featuredCommunities": {
     "openAsDefault": false,
     "spaces": [],