SQL Studio, Log Explorer and Pooler Fixes

What's changed

• SQL Studio no longer runs out of memory on large result sets; the agent got more headroom and a restart now returns a clear 503 instead of an empty error
• Log Explorer times out cleanly after 25 seconds with a retry hint instead of hanging on very large log volumes
• Turning the connection pooler off and on in quick succession now has a short cooldown, which stops it wedging in a half-deleted state
• The default PostgreSQL parameter groups log only statements slower than two seconds instead of every write, which keeps logs readable and searches fast; your own parameter group settings are respected