Link former Samachan users to SushiChan with one-time notification.

src/Miscellaneous/PSA.coffee

@@ -1,9 +1,14 @@
 PSA =
   init: ->
-    return unless g.SITE.software is 'yotsuba'
-    if g.BOARD.ID is 'qa'
+    if g.SITE.software is 'yotsuba' and g.BOARD.ID is 'qa'
       announcement = <%= html('Stay in touch with your <a href="https://www.4chan-x.net/qa_friends.html" target="_blank" rel="noopener">/qa/ friends</a>!') %>
-    return unless announcement
-    el = $.el 'div', {className: 'fcx-announcement'}, announcement
-    $.onExists doc, '.boardBanner', (banner) ->
-      $.after banner, el
+      el = $.el 'div', {className: 'fcx-announcement'}, announcement
+      $.onExists doc, '.boardBanner', (banner) ->
+        $.after banner, el
+    if 'samachan.org' of Conf['siteProperties'] and 'samachan' not in Conf['PSAseen']
+      el = $.el 'span',
+        <%= html('<a href="https://sushigirl.us/yakuza/res/776.html" target="_blank" rel="noopener">Looking for a new home?<br>Some former Samachan users are regrouping on SushiChan.</a><br>(a message from 4chan X)') %>
+      Main.ready ->
+        new Notice 'info', el
+        Conf['PSAseen'].push('samachan')
+        $.set 'PSAseen', Conf['PSAseen']

src/config/Config.coffee

@@ -1180,3 +1180,5 @@ Config =
   passMessageClosed: false
 
   'Prerequest Captcha': false
+
+  'PSAseen': [[]]