With max_new_per_check at 0 and no per-subscription limit, the budget is usize::MAX, and pending() bound it `as i64`: -1. SQLite reads LIMIT -1 as no limit; Postgres refuses it, so a feed's downloads failed. The new test fails with "LIMIT must not be negative" on Postgres without the clamp and passes with it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>