# Bug report: HP Smart Tank USB printers are not plug-and-play on Omarchy

## System
- Omarchy 4.0.3-1, kernel 7.2.4-arch1-2, CUPS 2.4.19-1, cups-filters 2.0.1-3
- HP Smart Tank 529 (520_540 series), USB vid:pid `03F0:4554`, SN `TH48Q4T074`, IEEE-1284 `MFG:HP;MDL:Smart Tank 520_540 series;CMD:PCL3GUI,...`

## Summary
Plugging in an HP Smart Tank 529 and using the default CUPS "Add Printer" flow creates a driverless/IPP-Everywhere queue that **fails on every job** with `universal filter failed` / `pdftopdf stopped with status 1`. HP drivers (hplip) are not installed on a fresh image, so there are no PPDs for the device and a normal user cannot print without terminal + `pacman` + driver setup.

## Steps to reproduce (fresh install)
1. Fresh Omarchy install, plug HP Smart Tank 529 into USB, power on.
2. Settings → Printers → Add Printer → pick `HP Smart Tank 520_540 series` (only driverless/IPP option offered).
3. Print anything (Ctrl+P in LibreOffice/PDF viewer). Every job fails:

```
cfFilterChain: pdftopdf (PID ...) stopped with status 1
PID ... (/usr/lib/cups/filter/universal) stopped with status 1
printer-state-message="universal filter failed."
```

## Expected
- Plug in → prints (A4/color), scan works, no terminal, no `sudo pacman`, no plugin download, no group edits.

## Root cause
- `hplip` is not shipped (only 29 generic CUPS PPDs on the image), and the driverless queue is broken for this PCL3GUI inkjet class.
- Enabling `ipp-usb` fights the kernel `usblp` driver — the USB device flaps (`usblp0: removed` repeatedly) and the hplip backend then fails with `open device failed stat=12`.
- A queue referencing an hplip PPD disappears entirely from CUPS if hplip is ever uninstalled, which makes PnP state fragile.
- Bonus: default mirror is a single server (`stable-mirror.omarchy.org`) that intermittently times out on resolve, so the needed package downloads fail unreliable times.

## Verified fix on this machine
```bash
sudo pacman -S hplip gutenprint ipp-usb cups-filters sane python-pyqt5 libusb usbutils wget python-pillow python-reportlab foomatic-db-gutenprint-ppds
sudo systemctl disable --now ipp-usb    # stop usblp/ipp friction
sudo lpadmin -p HPSmartTank -E \
  -m drv:///hp/hpcups.drv/hp-smart_tank_520_540_series.ppd \
  -v "hp:/usb/Smart_Tank_520_540_series?serial=TH48Q4T074"
sudo lpadmin -d HPSmartTank
```
After this, Ctrl+P in any app shows "HPSmartTank" and prints reliably even after USB unplug/replug. `hplip 1:3.26.4` supports this model.

## Requested
- Ship `hplip` + `gutenprint` + `foomatic-db-gutenprint-ppds` by default (or auto-suggest installing them when an HP USB printer is detected).
- When a driverless queue fails with "universal filter failed", fall back to the matching hplip PPD and show a readable hint ("install hplip") instead of a silent failure.
- Ensure `ipp-usb` does not break established `usblp`/`hp` queues on standard USB printing.
- Add official Arch mirrors as fallback in the default mirrorlist.