Initial snapshot ignores Postgres publication row filters

[michaelbarnes]

Observation

Postgres publication row filters (ALTER PUBLICATION ... ADD TABLE foo WHERE (...)) are not applied during PowerSync's initial snapshot. They take effect once WAL streaming begins, but the snapshot itself reads the full table. It would be great if we could include publication level filtering on the initial snapshot to reduce initial replication.

There's an open PR (#502 — Prefiltering during initial replication) that adds first-class support for filtering data during the snapshot, but it's binlog/MySQL-focused and not yet merged for Postgres.