Increase default batch_size from 200 to 400

[steve-chavez]

Problem

With the recent performance enhancements:

• perf: don't insert on every event loop iteration #233
• perf: use prepared statements for worker queries #234

Processing 400 req/s now has the same max CPU usage than 200 req/s, see loadtests:

• Old: https://github.com/supabase/pg_net/actions/runs/17269203113
• New: https://github.com/supabase/pg_net/actions/runs/17566969559

Solution

Increase batch_size from 200 to 400.

[steve-chavez]

Increase batch_size from 200 to 400.

We shouldn't do this, as it could cause existing webhooks to be rate limited by APIs.