fix(pgcli): Fix error when initializing pgcli command

[rgoomar]

Summary

Fix render pgcli failing with Error: flag accessed but not defined: command by bypassing ParseCommand for pgcli's arg parsing. This gets it into a working state.

Motivation

render pgcli is broken — any invocation hits the error because ParseCommand reflects over all cli struct tags on PSQLInput, including Command (tagged cli:"command"), which maps to a --command flag that only psql registers. pgcli is interactive-only and doesn't need that flag.

How to verify

1. render pgcli --help — should show help without error
2. render pgcli — should launch interactive database selection
3. render pgcli <postgres-id-or-name> — should connect directly
4. render pgcli <postgres-id-or-name> -- --some-pgcli-flag — should pass extra args through
5. render psql — should still work as before (no regression)

I ran all of these locally with

go build
./cli pgcli

Release notes

Fix `render pgcli` command failing with "flag accessed but not defined: command"