Restore migrations/0001_tools.sql byte for byte: an applied migration is never edited (test:pg refused it as changed after it was applied); 0004 carries the outbox note

ddiff --git a/migrations/0001_tools.sql b/migrations/0001_tools.sql
iindex 70ba110..8aa04ec 100644
---- a/migrations/0001_tools.sql
++++ b/migrations/0001_tools.sql
@@@ -4,7 +4,7 @@
  --
  -- Not here on purpose (plan T8, decision 4):
  --   guard_salt, guard_day, the minute/burst token buckets  -> Valkey (throttle state, worthless after a day)
----   the event outbox        -> migrations/0004_event_outbox.sql (openvibe-sdk createPgOutbox's table, as owner)
++--   the event outbox        -> openvibe-sdk createPgOutbox creates its own table at boot
  --   token_revocations       -> openvibe-sdk/auth createPgRevocationStore creates its own table at boot
  --
  -- `app` (the owning app, one row per app in the one database) has DEFAULT '' so scripts/migrate-to-postgres.js