fix(sat): the locator was already set, and the map was on top of everything

Two things reported together on the new tab.

The locator: the station's is on the ACTIVE PROFILE, not in a settings
key. keyStationMyGrid is a legacy key that EnsureDefault migrated into
the profile long ago and nothing writes any more, so reading it told an
operator with a perfectly good locator on screen that he had not set one
— and refused every pass prediction on the strength of it.

The map: Leaflet stacks its panes and controls up to z-index 1000, which
without a stacking context of their own float over the whole application
— Preferences opened behind the map, its Save and Close buttons under it.
The other three maps in OpsLog each carry `isolate` for exactly this
reason; this one was missing it.

frontend/src/components/SatellitePanel.tsx

@@ -415,8 +415,12 @@ export function SatellitePanel({ myGrid }: { myGrid: string }) {
       {err && <div className="px-2 text-[11px] text-danger shrink-0">{err}</div>}
 
       <div className="flex gap-1 flex-1 min-h-0">
-        {/* The map. */}
-        <div className="flex-1 min-w-0 rounded-lg overflow-hidden border border-border">
+        {/* The map. isolate is load-bearing, not tidiness: Leaflet stacks its
+            own panes and controls up to z-index 1000, which without a stacking
+            context of their own float over Preferences and every dialog in the
+            app — the map ends up on top of the very buttons that would close
+            it. */}
+        <div className="relative isolate z-0 flex-1 min-w-0 rounded-lg overflow-hidden border border-border">
           <div ref={divRef} className="h-full w-full" />
         </div>