fix(stats): leave our own host out of the peers

Favicon lookups for local accounts can add our own host to instances.
Also skip userinfo and IPv6 literals in the backfill migration.

priv/repo/migrations/20261028000000_backfill_instances_from_users.exs

@@ -13,7 +13,8 @@ defmodule Pleroma.Repo.Migrations.BackfillInstancesFromUsers do
       INSERT INTO instances (host, inserted_at, updated_at)
       SELECT DISTINCT host, now(), now()
       FROM (
-        SELECT substring(ap_id from '^[A-Za-z][A-Za-z0-9+.-]*://([^/:?#]+)') AS host
+        -- Skips userinfo; IPv6 literals give NULL and are left out.
+        SELECT substring(ap_id from '^[A-Za-z][A-Za-z0-9+.-]*://(?:[^/?#@]*@)?([^/:?#\\[]+)') AS host
         FROM users
         WHERE local = false AND ap_id IS NOT NULL
       ) AS hosts