✨ feat: feat: add consolidated Installed Drivers page

New sidebar entry "Installed" shows all installed drivers grouped by
category (Kernels, Video/GPU, Wi-Fi, Bluetooth, Printers, etc.) in a
single view.  Each group is displayed as a card with a category header,
item count, status badges (Running, Active, Detected, Installed) and
Remove buttons for module/firmware/peripheral drivers.

The page is populated in detection phase 2 alongside existing category
sections, reusing the same DriverDatabase, MHWD, Mesa and Kernel data.

Also regenerated the POT, merged and translated 8 new strings across
all 29 supported languages, and compiled the .mo files.

New file:  ui/installed_page.py
Modified:  ui/window.py (import, sidebar, stack, breakpoints, populate)
Updated:   locale/*.po, locale/biglinux-driver-manager.pot
Compiled:  usr/share/locale/*/LC_MESSAGES/big-driver-manager.mo

Author: talesam