Restores parked, previously-uncommitted PowerShell improvements:
- zbackup / zbackup_and_sync require an explicit target: bare invocation
now prints usage instead of quietly backing up everything; 'all' does
what bare used to (matching zdeploy). setup_backup_schedule.ps1 passes
'all' to the scheduled task; both tolerate switch-style args.
- zbackup parses more DATABASE_URL styles: strips surrounding quotes
(Prisma convention), accepts postgres:// and postgresql+driver://
schemes, and treats the port as optional (defaults to 5432).
- Invoke-Ec2Step survives ssh stderr warnings: under ErrorActionPreference
'Stop', PS 5.1 turns any native stderr line (e.g. Docker's COMPOSE_BAKE
deprecation notice) into a terminating NativeCommandError, aborting a
deploy that actually succeeded. Drop to Continue locally and flatten
stderr so only the real exit code decides success.
Config-driven PowerShell scripts to run infrastructure tasks (deploy, restart, backup, diagnostics) yourself instead of having an AI agent orchestrate them, to save agent tokens. Environment specifics live in zconfig.json (gitignored).
