Features

Add support for single-command to run a SQL command and exit.
- Command line option -c or --command.
- You can specify multiple times.
- Runs one statement at a time, like -f, and can be combined with -f:
  both run, the same way psql does.
Add support for forcing destructive commands without confirmation.
- Command line option -y or --yes.
- Skips the destructive command confirmation prompt when enabled.
- Useful for automated scripts and CI/CD pipelines.
Add a -t/--tuples-only command line option that prints the rows and
nothing else, matching psql: no column headers, no title, no status footer
and no timing line. The configured table format is left untouched, so \T
still reports it and can still change it mid-session.
Add support for executing SQL commands from file and exit.
- Command line option -f or --file.
- Multiple files can be specified.
- Files run one statement at a time, like psql, so a \watch only
  repeats its own statement (and a bare \watch re-runs the statement
  before it), instead of re-running the whole file. A backslash command
  spans only its own line, also like psql, so a metacommand followed by
  SQL on the next line does not swallow the SQL.

Bug fixes

Fix special commands being broken while explain mode (F5) is on. Every input
was prefixed with EXPLAIN (...) and sent to the server as SQL, including
backslash commands and the bare words exit/quit, so \q, \d,
\i, named queries and \G all failed with syntax error at or near "\" and there was no way to leave explain mode or quit. Special commands
are now detected first and the EXPLAIN prefix is applied only to real SQL.
Fix -l/--list and --ping discarding the connection string. The
positional argument was unconditionally replaced with postgres, which
also threw away a connection URI or key=value conninfo (host, user, port,
sslmode, everything) and silently fell back to a local socket connection
as the OS user. The database argument is now kept, like psql; only when no
database is given at all does the listing connect to postgres.