feat: import Chinese-localized Buzz source snapshot

Signed-off-by: cls_宁波本机 <908705107@qq.com>

migrations/0023_push_match_gate.sql

@@ -0,0 +1,43 @@
+-- T1b push gate: skip push_match_queue enqueue entirely for communities with
+-- no active, endpoint-enabled, unexpired push lease. In lease-less communities
+-- (most of them) every durable message currently pays the full matcher cost
+-- (enqueue + claim + lease scan + delete) to conclude "notify no one".
+--
+-- Correctness protocol (write-amp plan rev 3, [R2/R3]):
+--   * The gate lives HERE, in the events trigger, so every durable producer is
+--     covered — including internal paths that bypass live dispatch.
+--   * Lost-wake race: a naive EXISTS check could read "no lease" while a lease
+--     activation commits concurrently, silently dropping that user's wake with
+--     no retry. Closed with a per-community advisory lock held to transaction
+--     end: event inserts take the lock SHARED (concurrent with each other),
+--     lease transitions that can make eligibility true take it EXCLUSIVE
+--     (crates/buzz-db/src/push.rs: accept_lease_event and replace_lease).
+--     The conflict forces a total order: either the event's check sees the
+--     committed lease, or the activation strictly follows the event's commit —
+--     in which case no lease existed when the event was accepted and no wake
+--     was owed. The lease-activation backfill is product recovery coverage
+--     only and is not part of this proof.
+--   * Lock key domain 'buzz_push_gate:' is distinct from the audit lock
+--     ('buzz_audit:') and both lease-address lock families.
+CREATE OR REPLACE FUNCTION enqueue_push_match_job() RETURNS trigger
+LANGUAGE plpgsql AS $$
+BEGIN
+    -- Keep this allowlist identical to the relay's validated NIP-PL descriptor.
+    IF NEW.kind IN (7, 9, 1059, 40007, 46010) THEN
+        PERFORM pg_advisory_xact_lock_shared(
+            hashtextextended('buzz_push_gate:' || NEW.community_id::text, 0));
+        IF EXISTS (
+            SELECT 1 FROM push_leases
+            WHERE community_id = NEW.community_id
+              AND active
+              AND endpoint_enabled
+              AND expires_at > EXTRACT(EPOCH FROM now())::bigint
+        ) THEN
+            INSERT INTO push_match_queue (community_id, event_id)
+            VALUES (NEW.community_id, NEW.id)
+            ON CONFLICT DO NOTHING;
+        END IF;
+    END IF;
+    RETURN NEW;
+END
+$$;