Cover the shell, capture, browsers, and networking in the manual

Add chapters for the top bar and its panels, screenshots and recording,
toggles/idle/screensaver, browsers, shell plugins, and networking, which
collects the Wi-Fi, DNS, firewall, and Tailscale material that was spread
across the FAQ, TUIs, and services chapters.

Fill smaller gaps in the existing chapters: user hooks, autostart, menu
extensions, printing, power profiles, factory reset, drive and user
passwords, passwordless sudo, firmware updates, display text size, and
the LocalSend share menu.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

manual/38-backgrounds.md

@@ -0,0 +1,7 @@
+# Backgrounds
+
+Every theme ships with its own set of backgrounds, and you can add extras of your own in `~/.config/omarchy/backgrounds/[theme]`. If you want to add an extra background image to, say, the nord theme, you just put the file in `~/.config/omarchy/backgrounds/nord`.
+
+You can do this most easily by going to _Install > Style > Background_ in the Omarchy Menu. That'll bring up the folder where the backgrounds for that theme is stored. Hit `Super + Shift + F` to start another file manager, find your background, copy it over.  Now it'll be included in the choices of backgrounds you can select between using `Super + Ctrl + Space`.
+
+You can find a huge collection of cool curated backgrounds on https://github.com/dharmx/walls.