fix: use logical OR in postgres connection drain loop

[LautaroPetaccio]

Summary

The connection drain loop in postgres.ts used bitwise OR (|) instead of logical OR (||) to check if the pool still had active connections:

while (!finished && pool.totalCount | pool.idleCount | pool.waitingCount) {

Bitwise OR on integers happens to produce the same truthiness as logical OR for non-negative values (returns 0 only when all are 0), so this worked by accident. Changed to logical OR with proper parentheses for correctness and clarity.

Test plan

• Verify graceful shutdown still drains connections properly