Add welcome dashboard as default view

Replace the All Services grid as the landing view with a
Nextcloud-style welcome dashboard:

- Greeting (time-of-day), "Welcome to Your Sovereign Digital &
  Financial Life" headline, version + role meta line
- Status cards: Systems Operational, Network (LAN/WAN/hostname),
  Bitcoin sync progress with ETA, and available-updates card
- Calm drifting orb background animation (transform-only,
  disabled under prefers-reduced-motion)
- Services grid stays mounted but hidden until the user browses
  (Browse button, search, or a nav category); Dashboard nav item
  returns to the welcome view
- Move role badge and autolaunch preference out of the sidebar;
  autolaunch toggle now lives in the Systems Operational modal
- Remove LAN/WAN chip from the topbar; IPs live on the Network card

app/sovran_systemsos_web/static/css/modals.css

@@ -1505,6 +1505,15 @@
   margin-top: 5px;
 }
 
+.sysprefs {
+  padding: 0 24px 20px;
+  border-top: 1px solid var(--border);
+  margin-top: 16px;
+  padding-top: 14px;
+}
+
+.sysprefs .autolaunch-section .feature-card { padding: 2px 0 0; }
+
 .sysfineprint {
   font-size: 0.72rem;
   color: var(--text-3);