gate2: fix mail plugin migration 0009 — guard UPDATE for missing deleted_at column on fresh DB

app/plugins/builtins/mail/migrations/0009_remove_mail_soft_delete.sql

@@ -1,4 +1,15 @@
 -- Remove soft-delete (deleted_at) logic from mails
 -- Mails now use standard mail program logic: folder_id for Trash, permanent DELETE for Trash empty
 -- This migration clears all existing deleted_at values so no mails are hidden
+-- Safe for fresh installs: only update if column exists
+DO $$
+BEGIN
+    IF EXISTS (
+        SELECT 1 FROM information_schema.columns
+        WHERE table_schema = 'public'
+          AND table_name = 'mails'
+          AND column_name = 'deleted_at'
+    ) THEN
         UPDATE mails SET deleted_at = NULL;
+    END IF;
+END $$;