make configurable wal auto checkpoint (#2242)

config-example.yaml

@@ -168,6 +168,11 @@ database:
     # https://www.sqlite.org/wal.html
     write_ahead_log: true
 
+    # Maximum number of WAL file frames before the WAL file is automatically checkpointed.
+    # https://www.sqlite.org/c3ref/wal_autocheckpoint.html
+    # Set to 0 to disable automatic checkpointing.
+    wal_autocheckpoint: 1000
+
   # # Postgres config
   # Please note that using Postgres is highly discouraged as it is only supported for legacy reasons.
   # See database.type for more information.