Rebuild Home around what this desktop already knows

Home led with a diagram of the attached monitor -- DP-2, 4500 x 3000, 1.13x
scale, XRGB2101010 -- which is Displays-page data, was the largest thing on the
screen, and has never been needed there. Under it sat a permanently open search
field for a weather location that is set about once a year, and then roughly
half a page of nothing.

It now opens with the two or three things somebody would open Home to do:
starting or ending a focus session, Do Not Disturb, and what is running. The Do
Not Disturb switch is disabled and says why while a mode is holding it, so it
cannot appear to be a control that is being ignored.

Findings sit above a reassurance line, the same shape the Firewall and
Containers pages use. Each finding names the page that can resolve it, because a
home page reporting a problem it cannot help with is only an alarm. On this
machine that is one finding today -- PostgreSQL and Redis reachable from the
network -- above "27 health checks pass, 522 GB free, snapshots ran at 02:00".
"Do next" appears only when there is something in it.

Weather stays, as the greeting's second line rather than a card with a search
box open, and its picker is collapsed behind the current location.

FocusModes was missing `import qs.config`, so DesktopPreferences was undefined
and the modes list came back undefined with it -- shipped two commits ago with
nothing noticing, because until Home referenced the service no isolated shell
had ever instantiated it. Focus modes would have quietly had no modes. Pulling
these services together on one page is what surfaced it.

LocationPicker gained a picked signal, the same way DisplayModePicker did, so a
container can put the search away without reaching into it.

Claude-Session: https://claude.ai/code/session_01BRvzt4H8XXLPVH5MyYdk9L

config/dot/quickshell/services/FocusModes.qml

@@ -19,6 +19,7 @@ pragma Singleton
 import Quickshell
 import Quickshell.Hyprland
 import QtQuick
+import qs.config
 
 Singleton {
     id: root