fix(cli): detect dead db connections (CLI-2207)

[7ttp]

TL;DR

fixes supabase db reset and supabase start hanging forever with no error when the database connection dies while migrations are being applied

whats broken?

node-postgres silently discards every protocol frame once a socket stops being writable, while still reporting the write as successful, so the whole batch goes nowhere and the CLI waits forever on a reply the server was never asked for

it also leaves TCP keepalive off by default, where the Go CLI's driver had it on, so a peer that dies without a FIN or RST is never noticed either

fixed now by:

• failing a batch that never reached the wire as a connection error, carrying the driver's own reason instead of blaming the migration's first statement
• discarding that pooled connection, so the next batch redials instead of writing into the same dead socket
• turning TCP keepalive on for every connection the CLI opens, so a silently dead peer is eventually detected instead of waited on

a server that stays alive but never answers still waits, matching the Go CLI, since that is indistinguishable from a long running statement

ref:

• closes: supabase db reset/start: migration-apply SQL pipeline stops mid-stream with no server-side counterpart #6244

[github-actions]

Supabase CLI preview

npx --yes https://pkg.pr.new/supabase/cli/supabase@13bea164bc41c232d4c7494daca095cc06bd9493

Preview package for commit 13bea16.