docs(schema): drop stale fence-attachment guidance

Remove the leftover schema.sql comment for the deleted blanket fence
bootstrap, and stop the attach helper's header from telling authors to
fence new tables, which contradicts docs/database.md Rule 1.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Signed-off-by: Nikolaj Goodger <ngoodger@squareup.com>

schema/functions/attach_community_write_fence.sql

@@ -1,6 +1,6 @@
--- Attach the universal fence to one community-scoped relation. Future
--- migrations must invoke this helper explicitly after CREATE/ALTER introduces
--- community_id; the migration lint enforces that contract.
+-- Attach the legacy universal fence to one community-scoped relation. Only
+-- tables fenced before fence retirement use it; new tenant tables rely on
+-- application admission and must not call it (docs/database.md Rule 1).
 CREATE FUNCTION attach_community_write_fence(target REGCLASS) RETURNS VOID
 LANGUAGE plpgsql AS $$
 DECLARE

schema/schema.sql

@@ -213,5 +213,3 @@ CREATE EXTENSION IF NOT EXISTS pgcrypto;
 \i seeds/operator_listener_outbox.sql
 \i seeds/relay_operator_audit.sql
 \i seeds/storage_accounting_snapshots.sql
-
--- Fence any community-scoped table that lacks an explicit attach.